The internal combustion engine control system includes an injector 3 (116) to supply fuel to an internal combustion engine 11, means 110 for calculating power distribution time for the injector, a sensor 105 to detect a valve opening of the injector, and means 112 for calculating and storing valve opening delay time, which is a difference between a power distribution start time and a valve opening detection time. When a power distribution time determination section 114 determines that the power distribution time for the injector is not less than a predetermined value, the valve opening delay time is calculated and stored. When the power distribution time for the injector is less than the predetermined value, the power distribution time for the injector is controlled based on the valve opening delay time stored in storing means to perform control to increase the injector power distribution time.