An engine start system which may be employed in automotive idle stop systems. The engine start system includes a pinion gear to be pushed to a ring gear coupled to an engine for achieving meshing engagement with the ring gear. After the pinion gear engages the ring gear, the engine start system starts to rotate the pinion gear using a starter motor to crank the engine. Specifically, when an engine restart request is made following an engine stop request, the engine start system waits until after the speed of the engine drops below a preselected gear engagable speed and then moves the pinion gear toward the ring gear without rotating the pinion gear. This minimizes the consumption of fuel in the vehicle in supplying electric power to the starter motor and a maximum level of mechanical noise arising from the engagement of the pinion gear with the ring gear.