diff --git a/tests/integration/defs/perf/utils.py b/tests/integration/defs/perf/utils.py
index 24222bb83f3b..d5b3cab6e4fc 100644
--- a/tests/integration/defs/perf/utils.py
+++ b/tests/integration/defs/perf/utils.py
@@ -22,6 +22,7 @@
 import signal
 import socket
 import subprocess
+import tempfile
 import threading
 import time
 from datetime import datetime
@@ -391,10 +392,17 @@ def start_server(self) -> None:
             "--host", self._host, "--port",
             str(self._port)
         ]
-        self._server_log_path = os.path.join(os.getcwd(),
-                                             "trtllm-serve-perf.log")
         print_info(f"Starting trtllm-serve: {' '.join(cmd)}")
-        self._server_log_file = open(self._server_log_path, "w")
+        # Cluster jobs can share a working directory. Create a unique log for
+        # each launch so another server cannot truncate its startup metrics.
+        self._server_log_file = tempfile.NamedTemporaryFile(
+            mode="w",
+            prefix="trtllm-serve-perf-",
+            suffix=".log",
+            dir=os.getcwd(),
+            delete=False)
+        self._server_log_path = self._server_log_file.name
+        print_info(f"trtllm-serve log: {self._server_log_path}")
         self._server_proc = subprocess.Popen(cmd,
                                              env=self.server_env,
                                              stdout=self._server_log_file,