A method of producing a golf ball with uniform thickness by, eliminating defective air between the cover and the core, an insufficient thickness of the cover and an uneven thickness of the cover wherein in the step of heat and compression molding to cover the core or an intermediate layer with shells molded from a cover material mainly composed of a thermoplastic resin, if the mold has a temperature of T1.degree. C. and the half shells start to flow at a temperature of T2.degree. C., T1 minus T2 is set within a range of -3.degree. C. to +10.degree. C.