import boto.iam import sys iam = boto.connect_iam() users = iam.get_all_users('/')['list_users_response']['list_users_result']['users'] for user in users: for key_result in iam.get_all_access_keys(user['user_name'])['list_access_keys_response']['list_access_keys_result']['access_key_metadata']: aws_access_key = key_result['access_key_id'] for TARGET_ACCESS_KEY in sys.argv[1:]: if aws_access_key == TARGET_ACCESS_KEY: print aws_access_key + ' : ' + user['user_name']