To provide a controller for an internal combustion engine, for properly performing restraint of rotational fluctuation of an engine according to fluctuation of the road surface only for the required time.

When the rotational fluctuation DNE of an engine 200 is larger than a comparative reference value DNHK, the fuel injection amount is increased, and the DNHK is changed according to a value of the rotational fluctuation DVW of wheels 110, 120, 130 and 140. In a case where the DVW exceeds a threshold value DVW1 and a vehicle travels on the bad road, the DNHK is set to a large value not to be exceeded by the DVW, and the limit air-fuel ratio is increased. In case where the DVW is less than the threshold value DVW2 and the vehicle travels on the good road, the DNHK is set to 0(zero). In traveling on the average road with the relationship of DVW2<DVW<DVW, the DNHK is increased as the DVW is increased. The DNHK is changed according to frequencies of fluctuation of the DVW.