Abstract: A method of producing a tungsten heavy alloy product according to a powder metallurgical procedure utilizing the injection molding technique which enables production of tungsten heavy alloy products having high dimensional accuracy and complex configuration and yet having high physical strength and toughness in high productivity and at low cost. A powder mixture of tungsten powder and nickel powder, iron powder or copper powder is mixed with an organic binder and they are kneaded together. The kneaded mixture is injection molded into a predetermined shape, and thereafter the binder is removed from the molded product. Subsequently, the molded product is sintered in a temperature range of from the melting point of the bond phase of nickel, iron or copper to +50.degree. C. relative to the melting point.