diff --git a/providers/cncf/kubernetes/src/airflow/providers/cncf/kubernetes/executors/kubernetes_executor.py b/providers/cncf/kubernetes/src/airflow/providers/cncf/kubernetes/executors/kubernetes_executor.py
index 0dcc01537cb78..6ca463ed422d0 100644
--- a/providers/cncf/kubernetes/src/airflow/providers/cncf/kubernetes/executors/kubernetes_executor.py
+++ b/providers/cncf/kubernetes/src/airflow/providers/cncf/kubernetes/executors/kubernetes_executor.py
@@ -300,8 +300,20 @@ def sync(self) -> None:
                 finally:
                     self.result_queue.task_done()
 
-                for result in self.completed:
-                    self._change_state(result)
+        failed = set()
+        while self.completed:
+            result = self.completed.pop()
+            try:
+                self._change_state(result)
+            except Exception as e:
+                self.log.exception(
+                    "Exception: %s when attempting to change state of %s to %s, re-queueing.",
+                    e,
+                    result,
+                    result.state,
+                )
+                failed.add(result)
+        self.completed = failed
 
         from airflow.providers.cncf.kubernetes.executors.kubernetes_executor_utils import ResourceVersion
 
diff --git a/providers/cncf/kubernetes/tests/unit/cncf/kubernetes/executors/test_kubernetes_executor.py b/providers/cncf/kubernetes/tests/unit/cncf/kubernetes/executors/test_kubernetes_executor.py
index bc1c2a97f55c7..302f6035c5528 100644
--- a/providers/cncf/kubernetes/tests/unit/cncf/kubernetes/executors/test_kubernetes_executor.py
+++ b/providers/cncf/kubernetes/tests/unit/cncf/kubernetes/executors/test_kubernetes_executor.py
@@ -1507,6 +1507,83 @@ def test_adopt_completed_pods_single_scheduler_unchanged(
             header_params={"Accept": "application/json;as=PartialObjectMetadataList;v=v1;g=meta.k8s.io"},
         )
 
+    @pytest.fixture
+    def completed_result(self):
+        """Factory for a KubernetesResults entry as ``_adopt_completed_pods`` would add to ``self.completed``."""
+
+        def _make(name):
+            return KubernetesResults(
+                key=TaskInstanceKey("dag", name, "run_id", 1, -1),
+                state="completed",
+                pod_name=name,
+                namespace="somens",
+                resource_version="0",
+                failure_details=None,
+            )
+
+        return _make
+
+    @pytest.fixture
+    def sync_ready_executor(self):
+        """An executor whose ``sync()`` exercises only the ``self.completed`` drain.
+
+        Both queues are mocked so their ``get_nowait`` raises ``Empty`` immediately (as an
+        empty queue would), and ``kube_scheduler`` is mocked, so the only behavior under test
+        is how ``sync()`` processes ``self.completed``.
+        """
+        from queue import Empty
+
+        executor = self.kubernetes_executor
+        executor.scheduler_job_id = "modified"
+        executor.kube_client = mock.MagicMock()
+        executor.kube_scheduler = mock.MagicMock()
+        executor.result_queue = mock.MagicMock()
+        executor.result_queue.get_nowait.side_effect = Empty
+        executor.task_queue = mock.MagicMock()
+        executor.task_queue.get_nowait.side_effect = Empty
+        executor.create_pods_after = None
+        executor.kube_config.worker_pods_creation_batch_size = 1
+        return executor
+
+    @mock.patch(
+        "airflow.providers.cncf.kubernetes.executors.kubernetes_executor.KubernetesExecutor._change_state"
+    )
+    def test_sync_drains_and_clears_completed(self, mock_change_state, sync_ready_executor, completed_result):
+        """``sync()`` processes every entry in ``self.completed`` exactly once and clears the set."""
+        executor = sync_ready_executor
+        results = {completed_result(name) for name in ("one", "two", "three")}
+        executor.completed = set(results)
+
+        executor.sync()
+
+        assert {call.args[0] for call in mock_change_state.call_args_list} == results
+        assert mock_change_state.call_count == len(results)
+        assert executor.completed == set()
+
+    @mock.patch(
+        "airflow.providers.cncf.kubernetes.executors.kubernetes_executor.KubernetesExecutor._change_state"
+    )
+    def test_sync_retains_completed_entry_on_change_state_failure(
+        self, mock_change_state, sync_ready_executor, completed_result
+    ):
+        """A ``self.completed`` entry whose ``_change_state`` raises is retained; the rest still drain."""
+        executor = sync_ready_executor
+        good_one = completed_result("good-one")
+        good_two = completed_result("good-two")
+        bad = completed_result("bad")
+        executor.completed = {good_one, good_two, bad}
+
+        def fail_only_bad(result):
+            if result is bad:
+                raise RuntimeError("boom")
+
+        mock_change_state.side_effect = fail_only_bad
+
+        executor.sync()
+
+        assert mock_change_state.call_count == 3
+        assert executor.completed == {bad}
+
     @pytest.mark.db_test
     def test_alive_other_scheduler_job_ids_does_not_detach_caller_session(self, session):
         """``_alive_other_scheduler_job_ids`` must use an independent (non-scoped) session.