A fuel metering control system for an internal combustion engine having a plurality of cylinders. The system includes an air/fuel ratio sensor and engine operating condition detecting means for detecting engine operating conditions at least including engine speed and engine load. The basic quantity of fuel injection is determined by retrieving mapped data according to the engine speed and engine load. An adaptive controller is provided to calculate a feedback correction coefficient to correct the quantity of basic fuel injection such that the detected air/fuel ratio is brought to a desired air/fuel ratio value is provided for calculating feedback correction coefficients to correct the quantity of fuel injection. The output quantity of fuel injection is determined on the basis of the basic quantity of fuel injection and the feedback correction coefficients, and in addition, fuel adhered on an intake manifold wall.