diff --git a/vllm/entrypoints/llm.py b/vllm/entrypoints/llm.py
index 2c961156bc84..2faee57633e9 100644
--- a/vllm/entrypoints/llm.py
+++ b/vllm/entrypoints/llm.py
@@ -34,7 +34,8 @@
                                           _cosine_similarity,
                                           _validate_score_input_lens,
                                           get_score_prompt)
-from vllm.entrypoints.utils import _validate_truncation_size
+from vllm.entrypoints.utils import (_validate_truncation_size,
+                                    log_non_default_args)
 from vllm.inputs import PromptType, SingletonPrompt, TextPrompt, TokensPrompt
 from vllm.inputs.parse import parse_and_batch_prompt
 from vllm.logger import init_logger
@@ -271,6 +272,8 @@ def __init__(
             **kwargs,
         )
 
+        log_non_default_args(engine_args)
+
         # Create the Engine (autoselects V0 vs V1)
         self.llm_engine = LLMEngine.from_engine_args(
             engine_args=engine_args, usage_context=UsageContext.LLM_CLASS)
diff --git a/vllm/entrypoints/openai/api_server.py b/vllm/entrypoints/openai/api_server.py
index 5b87aed06e9b..98260f09968a 100644
--- a/vllm/entrypoints/openai/api_server.py
+++ b/vllm/entrypoints/openai/api_server.py
@@ -48,8 +48,7 @@
                                          resolve_mistral_chat_template)
 from vllm.entrypoints.launcher import serve_http
 from vllm.entrypoints.logger import RequestLogger
-from vllm.entrypoints.openai.cli_args import (log_non_default_args,
-                                              make_arg_parser,
+from vllm.entrypoints.openai.cli_args import (make_arg_parser,
                                               validate_parsed_serve_args)
 # yapf conflicts with isort for this block
 # yapf: disable
@@ -94,7 +93,7 @@
     OpenAIServingTranscription, OpenAIServingTranslation)
 from vllm.entrypoints.openai.tool_parsers import ToolParserManager
 from vllm.entrypoints.utils import (cli_env_setup, load_aware_call,
-                                    with_cancellation)
+                                    log_non_default_args, with_cancellation)
 from vllm.logger import init_logger
 from vllm.reasoning import ReasoningParserManager
 from vllm.transformers_utils.config import (
diff --git a/vllm/entrypoints/openai/cli_args.py b/vllm/entrypoints/openai/cli_args.py
index 7f60fe713027..2d19e16883aa 100644
--- a/vllm/entrypoints/openai/cli_args.py
+++ b/vllm/entrypoints/openai/cli_args.py
@@ -255,15 +255,6 @@ def validate_parsed_serve_args(args: argparse.Namespace):
                         "--tool-call-parser")
 
 
-def log_non_default_args(args: argparse.Namespace):
-    non_default_args = {}
-    parser = make_arg_parser(FlexibleArgumentParser())
-    for arg, default in vars(parser.parse_args([])).items():
-        if default != getattr(args, arg):
-            non_default_args[arg] = getattr(args, arg)
-    logger.info("non-default args: %s", non_default_args)
-
-
 def create_parser_for_docs() -> FlexibleArgumentParser:
     parser_for_docs = FlexibleArgumentParser(
         prog="-m vllm.entrypoints.openai.api_server")
diff --git a/vllm/entrypoints/utils.py b/vllm/entrypoints/utils.py
index 87334f458fee..d8905fc14124 100644
--- a/vllm/entrypoints/utils.py
+++ b/vllm/entrypoints/utils.py
@@ -3,6 +3,7 @@
 
 import argparse
 import asyncio
+import dataclasses
 import functools
 import os
 import subprocess
@@ -13,10 +14,13 @@
 from fastapi.responses import JSONResponse, StreamingResponse
 from starlette.background import BackgroundTask, BackgroundTasks
 
+from vllm.engine.arg_utils import EngineArgs
+from vllm.entrypoints.openai.cli_args import make_arg_parser
 from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
                                               CompletionRequest)
 from vllm.logger import init_logger
 from vllm.platforms import current_platform
+from vllm.utils import FlexibleArgumentParser
 
 logger = init_logger(__name__)
 
@@ -295,3 +299,28 @@ def get_max_tokens(max_model_len: int, request: Union[ChatCompletionRequest,
                for val in (default_max_tokens, max_tokens, max_output_tokens,
                            default_sampling_params.get("max_tokens"))
                if val is not None)
+
+
+def log_non_default_args(args: Union[argparse.Namespace, EngineArgs]):
+    non_default_args = {}
+
+    # Handle argparse.Namespace
+    if isinstance(args, argparse.Namespace):
+        parser = make_arg_parser(FlexibleArgumentParser())
+        for arg, default in vars(parser.parse_args([])).items():
+            if default != getattr(args, arg):
+                non_default_args[arg] = getattr(args, arg)
+
+    # Handle EngineArgs instance
+    elif isinstance(args, EngineArgs):
+        default_args = EngineArgs()  # Create default instance
+        for field in dataclasses.fields(args):
+            current_val = getattr(args, field.name)
+            default_val = getattr(default_args, field.name)
+            if current_val != default_val:
+                non_default_args[field.name] = current_val
+    else:
+        raise TypeError("Unsupported argument type. " \
+        "Must be argparse.Namespace or EngineArgs instance.")
+
+    logger.info("non-default args: %s", non_default_args)