diff --git a/ironic/api/controllers/v1/port.py b/ironic/api/controllers/v1/port.py
index 2d43cb883c..0fbb14bd7d 100644
--- a/ironic/api/controllers/v1/port.py
+++ b/ironic/api/controllers/v1/port.py
@@ -16,6 +16,7 @@
 import datetime
 
 from ironic_lib import metrics_utils
+from oslo_log import log
 from oslo_utils import uuidutils
 import pecan
 from pecan import rest
@@ -37,6 +38,7 @@ from ironic.common import utils as common_utils
 from ironic import objects
 
 METRICS = metrics_utils.get_metrics_logger(__name__)
+LOG = log.getLogger(__name__)
 
 
 _DEFAULT_RETURN_FIELDS = ('uuid', 'address')
@@ -263,8 +265,27 @@ class PortCollection(collection.Collection):
     @staticmethod
     def convert_with_links(rpc_ports, limit, url=None, fields=None, **kwargs):
         collection = PortCollection()
-        collection.ports = [Port.convert_with_links(p, fields=fields)
-                            for p in rpc_ports]
+        collection.ports = []
+        for rpc_port in rpc_ports:
+            try:
+                port = Port.convert_with_links(rpc_port, fields=fields)
+            except exception.NodeNotFound:
+                # NOTE(dtantsur): node was deleted after we fetched the port
+                # list, meaning that the port was also deleted. Skip it.
+                LOG.debug('Skipping port %s as its node was deleted',
+                          rpc_port.uuid)
+                continue
+            except exception.PortgroupNotFound:
+                # NOTE(dtantsur): port group was deleted after we fetched the
+                # port list, it may mean that the port was deleted too, but
+                # we don't know it. Pretend that the port group was removed.
+                LOG.debug('Removing port group UUID from port %s as the port '
+                          'group was deleted', rpc_port.uuid)
+                rpc_port.portgroup_id = None
+                port = Port.convert_with_links(rpc_port, fields=fields)
+
+            collection.ports.append(port)
+
         collection.next = collection.get_next(limit, url=url, **kwargs)
         return collection
 
diff --git a/ironic/tests/unit/api/controllers/v1/test_port.py b/ironic/tests/unit/api/controllers/v1/test_port.py
index 183450aca5..0effedd640 100644
--- a/ironic/tests/unit/api/controllers/v1/test_port.py
+++ b/ironic/tests/unit/api/controllers/v1/test_port.py
@@ -203,6 +203,49 @@ class TestListPorts(test_api_base.BaseApiTest):
         # never expose the node_id
         self.assertNotIn('node_id', data['ports'][0])
 
+    # NOTE(dtantsur): apparently autospec does not work on class methods..
+    @mock.patch.object(objects.Node, 'get')
+    def test_list_with_deleted_node(self, mock_get_node):
+        # check that we don't end up with HTTP 400 when node deletion races
+        # with listing ports - see https://launchpad.net/bugs/1748893
+        obj_utils.create_test_port(self.context, node_id=self.node.id)
+        mock_get_node.side_effect = exception.NodeNotFound('boom')
+        data = self.get_json('/ports')
+        self.assertEqual([], data['ports'])
+
+    # NOTE(dtantsur): apparently autospec does not work on class methods..
+    @mock.patch.object(objects.Node, 'get')
+    def test_list_detailed_with_deleted_node(self, mock_get_node):
+        # check that we don't end up with HTTP 400 when node deletion races
+        # with listing ports - see https://launchpad.net/bugs/1748893
+        port = obj_utils.create_test_port(self.context, node_id=self.node.id)
+        port2 = obj_utils.create_test_port(self.context, node_id=self.node.id,
+                                           uuid=uuidutils.generate_uuid(),
+                                           address='66:44:55:33:11:22')
+        mock_get_node.side_effect = [exception.NodeNotFound('boom'), self.node]
+        data = self.get_json('/ports/detail')
+        # The "correct" port is still returned
+        self.assertEqual(1, len(data['ports']))
+        self.assertIn(data['ports'][0]['uuid'], {port.uuid, port2.uuid})
+        self.assertEqual(self.node.uuid, data['ports'][0]['node_uuid'])
+
+    # NOTE(dtantsur): apparently autospec does not work on class methods..
+    @mock.patch.object(objects.Portgroup, 'get')
+    def test_list_with_deleted_port_group(self, mock_get_pg):
+        # check that we don't end up with HTTP 400 when port group deletion
+        # races with listing ports - see https://launchpad.net/bugs/1748893
+        portgroup = obj_utils.create_test_portgroup(self.context,
+                                                    node_id=self.node.id)
+        port = obj_utils.create_test_port(self.context, node_id=self.node.id,
+                                          portgroup_id=portgroup.id)
+        mock_get_pg.side_effect = exception.PortgroupNotFound('boom')
+        data = self.get_json(
+            '/ports/detail',
+            headers={api_base.Version.string: str(api_v1.max_version())}
+        )
+        self.assertEqual(port.uuid, data['ports'][0]["uuid"])
+        self.assertIsNone(data['ports'][0]["portgroup_uuid"])
+
     def test_get_one(self):
         port = obj_utils.create_test_port(self.context, node_id=self.node.id)
         data = self.get_json('/ports/%s' % port.uuid)
diff --git a/releasenotes/notes/port-list-bad-request-078512862c22118e.yaml b/releasenotes/notes/port-list-bad-request-078512862c22118e.yaml
new file mode 100644
index 0000000000..3f0116159a
--- /dev/null
+++ b/releasenotes/notes/port-list-bad-request-078512862c22118e.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes rare race condition which resulted in the port list API returning
+    HTTP 400 (bad request) if some nodes were being removed in parallel.
+    See `bug 1748893 <https://bugs.launchpad.net/bugs/1748893>`_ for details.