To provide a fuel injection control device suitably correcting dispersion in an injector injecting amount among cylinders, and achieving high-precision air-fuel ratio control.

This fuel injection control device for an engine is provided with a by-cylinder rich/lean air-fuel ratio controlling means A6 for intentionally controlling a target air-fuel ratio to be a rich air-fuel ratio or a lean air-fuel ratio cylinder-by-cylinder or bank-by-bank; a by-cylinder correction amount calculating means A4 for estimating an actual fuel injection amount cylinder-by- cylinder or bank-by-bank from a deviation between an actual air-fuel ratio of each cylinder and the target air-fuel ratio, and calculating the fuel correction amount cylinder-by-cylinder or bank-by-bank from the estimated value, in a period of by-cylinder rich/lean air-fuel ratio controlling by the by-cylinder rich/ lean air-fuel ratio controlling means A6. The fuel injection amount cylinder-by- cylinder or bank-by-bank is corrected with the fuel correction amount calculated by the by-cylinder correction amount calculating means A4.