Process for the manufacture of a golf club head comprising a peripheral shell (3) composed of a number of walls (5, 6, 7, 8), produced by injection of a plastic material (M1), which form an inner space (11) containing at least one inner insert (10, 100, 200) immobilized by partial coating of the plastic material of the shell (3). Prior to injection of the shell (3), an assembly comprising a fusible core (13) of a second material (M2) with a lower melting point than that of said plastic material (M1), is disposed and immobilized in the mould in the space between the mould walls and the assembly, so as to coat the fusible core (13) and all or part of the free part of said insert (10, 100, 200). Finally, all or part of the fusible core is eliminated to free an inner volume constituting the inner space (11).