The synthesis and characterization of two five-coordinate platinum(II) complexes of general formula [PtCl(SnMe(n)Cl3-n)(2,9-Me2-1,10-phenanthroline) (diethylfumarate)] (n = 1, 2) are described. The bimetallic species were tested on the neuroblastoma cell line SK-N-BE and a considerable inhibition of cellular proliferation was detected; the bimetallic species were also able to induce neuronal differentiation, as did retinoic acid, a well-known neuroblastoma differentiating agent.