An intake system for a V-type internal combustion engine having two banks. The intake system is comprised of two sub-collectors disposed above the respective two banks of the engine and fluidly connected with cylinders in the banks. A main collector is disposed above and between the two banks of the engine and fluidly connected through a throttle device with the two sub-collectors. The main collector is supplied with air from an air filter. The throttle device is located at the rear end side of the engine and has throttle valves which respsectively control air flows to the two sub-collectors in response to operation of an accelerator pedal.