Treatment of disseminated melanoma is still a difficult issue. Obvious achievements of recent years proves efficacy of immunologic approachees in this field. The ability of melatonin and metformin to decrease metabolic immunosuppression was shown in many experimental studies. Some literature data confirm the possibility of increasing efficacy of melatonin with dacarbazine (DTIC) and metformin with DTIC combinations. We hypothesized that this combinations could be more effective than DTIC monotherapy in terms of response rate and time to progression.