A control system for an internal combustion engine calculates an amount of fuel to be supplied to the engine based on load on the engine, and estimates an amount of fuel adhering to an inner wall surface of an intake passage of the engine and an amount of fuel carried off the fuel adhering to the inner wall surface of the intake passage, based on an adherent fuel-determining parameter indicative of a fuel transfer characteristic of the engine. The amount of fuel to be supplied to the engine is corrected based on the amount of fuel adhering to the inner wall surface of the intake passage and the amount of fuel carried off the fuel adhering to the inner wall surface of the intake passage to determine a corrected amount of fuel supplied to the engine. The corrected amount of fuel to be supplied to the engine is injected into the intake passage. The timing of the fuel injection is controlled based on the adherent fuel-determining parameters.