Disclosed is a method for simply producing, with high reproducibility, a composite metal cyanide complex catalyst having an organic ligand, which catalyst has high catalytic activity, small particle sizes and high uniformity in particle size. Specifically disclosed is a method for producing a composite metal cyanide complex catalyst having an organic ligand, which comprises a step (a) for obtaining a liquid containing a composite metal cyanide complex by bringing an aqueous metal halide compound solution into contact with an aqueous transition metal cyanide solution in a laminar flow state, and a step (b) for obtaining a dispersion liquid containing a composite metal cyanide complex catalyst having an organic ligand by mixing the liquid containing a composite metal cyanide complex with anorganic ligand.