Lovastatin, the drug used in the treatment of hypercholesterolaemia, has previously been reported to exert synergistic antitumour activity in a melanoma model in mice when used together with some immune response modifiers. In this study, we examined the antitumour effect of cisplatin augmented by its combined application with lovastatin, both in vitro and in vivo, in a murine melanoma model. The results of this study suggest that lovastatin may enhance the therapeutic effects of cisplatin in the treatment of malignant melanomas.