A vehicle heat exchanger includes heat exchangers overlapped with each other in an airflow direction. The heat exchangers include heat exchanger tubes arranged side by side with each other. The heat exchangers include outer fins interposed between neighboring heat exchanger tubes. The heat exchangers includes header pipes connecting and communicating with both ends of the heat exchanger tubes for heat-conducting media to circulate through the heat exchanger tubes and header pipes. The vehicle heat exchanger includes a reservoir in communication with one of the header pipes for reserving a heat-conducting medium. The reservoir is fixed to a header pipe of the largest one of the heat exchangers.