diff --git a/backend/app/api/routes/scan.py b/backend/app/api/routes/scan.py
index 33c03df..9b1d8d2 100644
--- a/backend/app/api/routes/scan.py
+++ b/backend/app/api/routes/scan.py
@@ -20,6 +20,34 @@ from app.services.zigbee_service import build_zigbee_properties
 _ZIGBEE_TYPES = {"zigbee_coordinator", "zigbee_router", "zigbee_enddevice"}
 
 
+def build_mac_property(mac: str | None) -> list[dict[str, Any]]:
+    """Build a NodeProperty list carrying a device MAC address.
+
+    Shape matches the frontend ``NodeProperty`` type
+    (``{key, value, icon, visible}``). Hidden by default — the user opts in to
+    showing it on the canvas card from the right panel. Returns an empty list
+    when no MAC is known.
+    """
+    if not mac:
+        return []
+    return [{"key": "MAC", "value": mac, "icon": None, "visible": False}]
+
+
+def merge_mac_property(
+    props: list[dict[str, Any]] | None, mac: str | None
+) -> list[dict[str, Any]]:
+    """Append a MAC NodeProperty to ``props`` unless one is already present.
+
+    Preserves any user-supplied properties (and an existing MAC row's
+    visibility) untouched. Used on approve so the scanned MAC is not lost.
+    """
+    out = [dict(p) for p in (props or [])]
+    if not mac or any(p.get("key") == "MAC" for p in out):
+        return out
+    out.append({"key": "MAC", "value": mac, "icon": None, "visible": False})
+    return out
+
+
 class BulkActionRequest(BaseModel):
     device_ids: list[str]
 
@@ -134,13 +162,14 @@ async def bulk_approve_devices(
             label=device.hostname or device.friendly_name or device.ip or "device",
             type=node_type,
             ip=device.ip,
+            mac=device.mac,
             hostname=device.hostname,
             status="online" if is_zigbee else "unknown",
             services=device.services or [],
             ieee_address=device.ieee_address,
             properties=build_zigbee_properties(
                 device.ieee_address, device.vendor, device.model, device.lqi
-            ) if is_zigbee else [],
+            ) if is_zigbee else build_mac_property(device.mac),
             # Default to ping so the status checker actually polls the new node.
             # Without this the scheduler skips it (check_method NULL → no check).
             check_method="none" if is_zigbee else ("ping" if device.ip else None),
@@ -234,17 +263,21 @@ async def approve_device(
         raise HTTPException(status_code=409, detail="Device already processed")
     device.status = "approved"
     _is_zigbee = node_data.type in _ZIGBEE_TYPES
+    # Prefer the MAC discovered during the scan (stored on the pending device);
+    # fall back to whatever the approve payload carried.
+    _mac = device.mac or node_data.mac
     node = Node(
         label=node_data.label,
         type=node_data.type,
         ip=node_data.ip,
+        mac=_mac,
         hostname=node_data.hostname,
         status="online" if _is_zigbee else node_data.status,
         services=node_data.services or [],
         ieee_address=device.ieee_address,
         properties=build_zigbee_properties(
             device.ieee_address, device.vendor, device.model, device.lqi
-        ) if _is_zigbee else (node_data.properties or []),
+        ) if _is_zigbee else merge_mac_property(node_data.properties, _mac),
         check_method="none" if _is_zigbee else (node_data.check_method or ("ping" if node_data.ip else None)),
         check_target=None if _is_zigbee else node_data.check_target,
     )
diff --git a/backend/tests/test_scan.py b/backend/tests/test_scan.py
index 7199ea9..6feb0b9 100644
--- a/backend/tests/test_scan.py
+++ b/backend/tests/test_scan.py
@@ -698,6 +698,144 @@ async def test_bulk_approve_zigbee_populates_properties(
     assert node.check_method == "none"
 
 
+# --- MAC address propagation on approve (issue #168) ---
+
+def test_build_mac_property_returns_hidden_row():
+    from app.api.routes.scan import build_mac_property
+
+    assert build_mac_property("aa:bb:cc:dd:ee:ff") == [
+        {"key": "MAC", "value": "aa:bb:cc:dd:ee:ff", "icon": None, "visible": False}
+    ]
+
+
+def test_build_mac_property_empty_when_no_mac():
+    from app.api.routes.scan import build_mac_property
+
+    assert build_mac_property(None) == []
+    assert build_mac_property("") == []
+
+
+def test_merge_mac_property_appends_when_absent():
+    from app.api.routes.scan import merge_mac_property
+
+    existing = [{"key": "Custom", "value": "x", "icon": None, "visible": True}]
+    merged = merge_mac_property(existing, "aa:bb:cc:dd:ee:ff")
+    assert {"key": "MAC", "value": "aa:bb:cc:dd:ee:ff", "icon": None, "visible": False} in merged
+    # Existing prop preserved untouched.
+    assert existing[0] in merged
+
+
+def test_merge_mac_property_idempotent_and_preserves_visibility():
+    from app.api.routes.scan import merge_mac_property
+
+    existing = [{"key": "MAC", "value": "aa:bb:cc:dd:ee:ff", "icon": None, "visible": True}]
+    merged = merge_mac_property(existing, "aa:bb:cc:dd:ee:ff")
+    # No duplicate MAC row; user's visible=True choice kept.
+    macs = [p for p in merged if p["key"] == "MAC"]
+    assert len(macs) == 1
+    assert macs[0]["visible"] is True
+
+
+def test_merge_mac_property_noop_without_mac():
+    from app.api.routes.scan import merge_mac_property
+
+    existing = [{"key": "Custom", "value": "x", "icon": None, "visible": True}]
+    assert merge_mac_property(existing, None) == existing
+
+
+@pytest.mark.asyncio
+async def test_approve_device_copies_mac_to_node_and_properties(
+    client: AsyncClient, headers, pending_device, db_session
+):
+    """Approving a scanned device must carry its MAC onto the node + properties."""
+    from sqlalchemy import select
+
+    from app.db.models import Node as NodeModel
+    # Payload intentionally omits mac — it must come from the pending device.
+    res = await client.post(
+        f"/api/v1/scan/pending/{pending_device.id}/approve",
+        json={"label": "My Server", "type": "server", "ip": "192.168.1.100", "status": "unknown", "services": []},
+        headers=headers,
+    )
+    assert res.status_code == 200
+    node = (
+        await db_session.execute(select(NodeModel).where(NodeModel.ip == "192.168.1.100"))
+    ).scalar_one()
+    assert node.mac == "aa:bb:cc:dd:ee:ff"
+    mac_props = [p for p in node.properties if p["key"] == "MAC"]
+    assert mac_props == [
+        {"key": "MAC", "value": "aa:bb:cc:dd:ee:ff", "icon": None, "visible": False}
+    ]
+
+
+@pytest.mark.asyncio
+async def test_approve_device_does_not_duplicate_mac_property(
+    client: AsyncClient, headers, pending_device, db_session
+):
+    """If the approve payload already carries a MAC prop, don't add a second one."""
+    from sqlalchemy import select
+
+    from app.db.models import Node as NodeModel
+    res = await client.post(
+        f"/api/v1/scan/pending/{pending_device.id}/approve",
+        json={
+            "label": "My Server",
+            "type": "server",
+            "ip": "192.168.1.100",
+            "status": "unknown",
+            "services": [],
+            "properties": [
+                {"key": "MAC", "value": "aa:bb:cc:dd:ee:ff", "icon": None, "visible": True}
+            ],
+        },
+        headers=headers,
+    )
+    assert res.status_code == 200
+    node = (
+        await db_session.execute(select(NodeModel).where(NodeModel.ip == "192.168.1.100"))
+    ).scalar_one()
+    mac_props = [p for p in node.properties if p["key"] == "MAC"]
+    assert len(mac_props) == 1
+    # User's visibility choice is preserved.
+    assert mac_props[0]["visible"] is True
+
+
+@pytest.mark.asyncio
+async def test_bulk_approve_copies_mac_to_node_and_properties(
+    client: AsyncClient, headers, db_session
+):
+    """Bulk approve must also propagate the scanned MAC to node + properties."""
+    from sqlalchemy import select
+
+    from app.db.models import Node as NodeModel
+    device = PendingDevice(
+        id=str(uuid.uuid4()),
+        ip="192.168.1.55",
+        mac="11:22:33:44:55:66",
+        hostname="host-mac",
+        services=[],
+        suggested_type="generic",
+        status="pending",
+    )
+    db_session.add(device)
+    await db_session.commit()
+
+    res = await client.post(
+        "/api/v1/scan/pending/bulk-approve",
+        json={"device_ids": [device.id]},
+        headers=headers,
+    )
+    assert res.status_code == 200
+    node = (
+        await db_session.execute(select(NodeModel).where(NodeModel.ip == "192.168.1.55"))
+    ).scalar_one()
+    assert node.mac == "11:22:33:44:55:66"
+    mac_props = [p for p in node.properties if p["key"] == "MAC"]
+    assert mac_props == [
+        {"key": "MAC", "value": "11:22:33:44:55:66", "icon": None, "visible": False}
+    ]
+
+
 @pytest.mark.asyncio
 async def test_bulk_approve_sets_default_check_method(client: AsyncClient, headers, two_pending_devices, db_session):
     """Approved devices with an IP must default to ping; otherwise scheduler skips them."""
diff --git a/frontend/src/components/modals/PendingDevicesModal.tsx b/frontend/src/components/modals/PendingDevicesModal.tsx
index 973b492..1f770ed 100644
--- a/frontend/src/components/modals/PendingDevicesModal.tsx
+++ b/frontend/src/components/modals/PendingDevicesModal.tsx
@@ -10,6 +10,7 @@ import { toast } from 'sonner'
 import { PendingDeviceModal, type PendingDevice } from '@/components/modals/PendingDeviceModal'
 import type { NodeType, ServiceInfo } from '@/types'
 import { buildZigbeeProperties, isZigbeeType } from '@/utils/zigbeeProperties'
+import { buildMacProperty } from '@/utils/macProperty'
 
 interface PendingDevicesModalProps {
   open: boolean
@@ -255,11 +256,12 @@ export function PendingDevicesModal({ open, onClose, highlightId, initialStatus
       const fallbackLabel = deviceLabel(device)
       const type = (device.suggested_type ?? 'generic') as NodeType
       const zigbee = isZigbeeType(type)
-      const properties = zigbee ? buildZigbeeProperties(device) : []
+      const properties = zigbee ? buildZigbeeProperties(device) : buildMacProperty(device.mac)
       const nodeData = {
         label: fallbackLabel,
         type,
         ip: device.ip ?? undefined,
+        mac: device.mac ?? undefined,
         hostname: device.hostname ?? undefined,
         status: zigbee ? 'online' : 'unknown',
         services: (device.services ?? []) as ServiceInfo[],
@@ -325,10 +327,11 @@ export function PendingDevicesModal({ open, onClose, highlightId, initialStatus
             label: deviceLabel(d),
             type,
             ip: d.ip ?? undefined,
+            mac: d.mac ?? undefined,
             hostname: d.hostname ?? undefined,
             status: zigbee ? ('online' as const) : ('unknown' as const),
             services: (d.services ?? []) as ServiceInfo[],
-            properties: zigbee ? buildZigbeeProperties(d) : [],
+            properties: zigbee ? buildZigbeeProperties(d) : buildMacProperty(d.mac),
           },
         })
       })
diff --git a/frontend/src/components/modals/__tests__/PendingDevicesModal.test.tsx b/frontend/src/components/modals/__tests__/PendingDevicesModal.test.tsx
index 6164950..4cbcf97 100644
--- a/frontend/src/components/modals/__tests__/PendingDevicesModal.test.tsx
+++ b/frontend/src/components/modals/__tests__/PendingDevicesModal.test.tsx
@@ -13,6 +13,7 @@ const mockApprove = vi.fn()
 const mockHide = vi.fn()
 const mockPending = vi.fn()
 const mockHidden = vi.fn()
+const mockAddNode = vi.fn()
 
 vi.mock('@/api/client', () => ({
   scanApi: {
@@ -69,7 +70,7 @@ const DEVICE_ZIGBEE = {
 beforeEach(() => {
   vi.clearAllMocks()
   vi.mocked(useCanvasStore).mockReturnValue({
-    addNode: vi.fn(),
+    addNode: mockAddNode,
     scanEventTs: 0,
   } as unknown as ReturnType<typeof useCanvasStore>)
   // setState is used by injectAutoEdges
@@ -174,6 +175,34 @@ describe('PendingDevicesModal', () => {
     await waitFor(() => expect(mockBulkApprove).toHaveBeenCalledWith(['dev-a', 'dev-b']))
   })
 
+  it('bulk approve carries the scanned MAC onto the canvas node (#168)', async () => {
+    render(<PendingDevicesModal {...baseProps} />)
+    await waitFor(() => expect(screen.getByTestId('pending-card-dev-a')).toBeInTheDocument())
+    fireEvent.click(screen.getByRole('button', { name: 'Select mode' }))
+    fireEvent.click(screen.getByTestId('pending-card-dev-a'))
+    fireEvent.click(screen.getByTestId('pending-card-dev-b'))
+    fireEvent.click(screen.getByRole('button', { name: /Approve \(2\)/ }))
+    await waitFor(() => expect(mockAddNode).toHaveBeenCalledTimes(2))
+
+    // dev-a is an IP device with a MAC → node carries mac + a MAC property row.
+    const ipNode = mockAddNode.mock.calls
+      .map((c) => c[0])
+      .find((n) => n.id === 'n1')
+    expect(ipNode.data.mac).toBe('aa:bb:cc:dd:ee:01')
+    expect(ipNode.data.properties).toContainEqual({
+      key: 'MAC',
+      value: 'aa:bb:cc:dd:ee:01',
+      icon: null,
+      visible: false,
+    })
+
+    // dev-b is zigbee with no MAC → no MAC property row.
+    const zbNode = mockAddNode.mock.calls
+      .map((c) => c[0])
+      .find((n) => n.id === 'n2')
+    expect(zbNode.data.properties.some((p: { key: string }) => p.key === 'MAC')).toBe(false)
+  })
+
   it('bulk hide calls API with selected ids', async () => {
     render(<PendingDevicesModal {...baseProps} />)
     await waitFor(() => expect(screen.getByTestId('pending-card-dev-a')).toBeInTheDocument())
diff --git a/frontend/src/utils/__tests__/macProperty.test.ts b/frontend/src/utils/__tests__/macProperty.test.ts
new file mode 100644
index 0000000..166f3fb
--- /dev/null
+++ b/frontend/src/utils/__tests__/macProperty.test.ts
@@ -0,0 +1,16 @@
+import { describe, it, expect } from 'vitest'
+import { buildMacProperty } from '../macProperty'
+
+describe('buildMacProperty', () => {
+  it('returns a hidden MAC property row for a MAC', () => {
+    expect(buildMacProperty('aa:bb:cc:dd:ee:ff')).toEqual([
+      { key: 'MAC', value: 'aa:bb:cc:dd:ee:ff', icon: null, visible: false },
+    ])
+  })
+
+  it('returns an empty array when MAC is null/undefined/empty', () => {
+    expect(buildMacProperty(null)).toEqual([])
+    expect(buildMacProperty(undefined)).toEqual([])
+    expect(buildMacProperty('')).toEqual([])
+  })
+})
diff --git a/frontend/src/utils/macProperty.ts b/frontend/src/utils/macProperty.ts
new file mode 100644
index 0000000..969da81
--- /dev/null
+++ b/frontend/src/utils/macProperty.ts
@@ -0,0 +1,9 @@
+import type { NodeProperty } from '@/types'
+
+/** Build the MAC address property row shown in the right panel.
+ * Hidden by default — the user opts in to showing it on the canvas card.
+ * Matches backend `build_mac_property`. Returns an empty array when no MAC. */
+export function buildMacProperty(mac?: string | null): NodeProperty[] {
+  if (!mac) return []
+  return [{ key: 'MAC', value: mac, icon: null, visible: false }]
+}