diff --git a/python/sglang/srt/environ.py b/python/sglang/srt/environ.py
index 2f9fcc9d1..db9774f31 100644
--- a/python/sglang/srt/environ.py
+++ b/python/sglang/srt/environ.py
@@ -145,6 +145,7 @@ class Envs:
     # Logging Options
     SGLANG_LOG_GC = EnvBool(False)
     SGLANG_LOG_FORWARD_ITERS = EnvBool(False)
+    SGLANG_LOG_MS = EnvBool(False)
     SGLANG_DISABLE_REQUEST_LOGGING = EnvBool(False)
 
     # Test & Debug
diff --git a/python/sglang/srt/utils/common.py b/python/sglang/srt/utils/common.py
index d6c10d06b..942bb26df 100644
--- a/python/sglang/srt/utils/common.py
+++ b/python/sglang/srt/utils/common.py
@@ -1203,8 +1203,8 @@ def configure_logger(server_args, prefix: str = ""):
             custom_config = orjson.loads(file.read())
         logging.config.dictConfig(custom_config)
         return
-    format = f"[%(asctime)s{prefix}] %(message)s"
-    # format = f"[%(asctime)s.%(msecs)03d{prefix}] %(message)s"
+    maybe_ms = ".%(msecs)03d" if envs.SGLANG_LOG_MS.get() else ""
+    format = f"[%(asctime)s{maybe_ms}{prefix}] %(message)s"
     logging.basicConfig(
         level=getattr(logging, server_args.log_level.upper()),
         format=format,