diff --git a/litellm/proxy/proxy_cli.py b/litellm/proxy/proxy_cli.py
index 2e677857573..242b8ba0c68 100644
--- a/litellm/proxy/proxy_cli.py
+++ b/litellm/proxy/proxy_cli.py
@@ -712,6 +712,7 @@ class ProxyInitializationHelpers:
         with prometheus configured as a callback in config.yaml, or the separate metrics server (always, since
         callbacks may also be enabled from the DB after startup).
         """
+        import shutil
         import tempfile
 
         from litellm.proxy.prometheus_cleanup import wipe_directory
@@ -731,8 +732,20 @@ class ProxyInitializationHelpers:
             multiproc_dir, action = configured_dir, "Using existing"
         else:
             # Unique per boot: a fixed shared name lets a second proxy on this host wipe the first one's counters.
+            import atexit
+
             multiproc_dir, action = tempfile.mkdtemp(prefix="litellm_prometheus_multiproc_"), "Auto-created"
 
+            # Only the creating process removes the dir on exit. Forked workers share it and
+            # must not delete samples their siblings are still writing.
+            creator_pid = os.getpid()
+
+            def _cleanup_auto_created_dir() -> None:
+                if os.getpid() == creator_pid:
+                    shutil.rmtree(multiproc_dir, ignore_errors=True)
+
+            atexit.register(_cleanup_auto_created_dir)
+
         os.environ["PROMETHEUS_MULTIPROC_DIR"] = multiproc_dir
         print(f"LiteLLM: {action} PROMETHEUS_MULTIPROC_DIR={multiproc_dir}")
         return multiproc_dir
diff --git a/tests/unit/proxy/test_prometheus_cleanup.py b/tests/unit/proxy/test_prometheus_cleanup.py
index 95903540c47..65163e7eb65 100644
--- a/tests/unit/proxy/test_prometheus_cleanup.py
+++ b/tests/unit/proxy/test_prometheus_cleanup.py
@@ -146,13 +146,15 @@ class TestMaybeSetupPrometheusMultiprocDir:
             os.environ.pop("prometheus_multiproc_dir", None)
 
             # Should not raise TypeError
-            ProxyInitializationHelpers._maybe_setup_prometheus_multiproc_dir(
+            result_dir = ProxyInitializationHelpers._maybe_setup_prometheus_multiproc_dir(
                 num_workers=4,
                 litellm_settings=litellm_settings,
             )
 
             # Cleanup
             os.environ.pop("PROMETHEUS_MULTIPROC_DIR", None)
+            if result_dir is not None:
+                shutil.rmtree(result_dir, ignore_errors=True)
 
     @pytest.mark.parametrize(
         "num_workers, litellm_settings",
@@ -200,6 +202,7 @@ class TestMaybeSetupPrometheusMultiprocDir:
 
             # Cleanup
             os.environ.pop("PROMETHEUS_MULTIPROC_DIR", None)
+            shutil.rmtree(result_dir, ignore_errors=True)
 
     @pytest.mark.parametrize(
         "litellm_settings",
@@ -227,6 +230,7 @@ class TestMaybeSetupPrometheusMultiprocDir:
             assert os.path.isdir(result_dir)
 
             os.environ.pop("PROMETHEUS_MULTIPROC_DIR", None)
+            shutil.rmtree(result_dir, ignore_errors=True)
 
     def test_lowercase_env_var_is_reused_and_exported_uppercase(self, tmp_path):
         """prometheus_client honours both spellings; the metrics server only reads the uppercase one."""