diff --git a/aider/main.py b/aider/main.py
index b66104881..9efcc9d58 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -5,6 +5,7 @@ from pathlib import Path
 
 import git
 import litellm
+from dotenv import load_dotenv
 from streamlit.web import cli
 
 from aider import __version__, models
@@ -287,7 +288,8 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
     cmd_line = scrub_sensitive_info(args, cmd_line)
     io.tool_output(cmd_line, log_only=True)
 
-    # todo: load .env using filename args.env_file
+    if args.env_file:
+        load_dotenv(args.env_file)
 
     if args.anthropic_api_key:
         os.environ["ANTHROPIC_API_KEY"] = args.anthropic_api_key