An automatic stop/start controller for an engine which automatically stops and starts the engine without operation of an ignition key. In automatically stopping the engine without operation of the ignition key, a control means prevents an automatic stop of the engine if a direction indicator of the vehicle is activated. If the direction indicator is activated after the engine is automatically stopped, the control means immediately automatically starts the engine without operation of the ignition key. The control means also prevents an automatic stop of the engine unless the distance traveled by a vehicle, after the engine has automatically started, is greater than a predetermined automatic stop prohibit distance.