Background: Use of ICI changed the treatment of Advanced Cutaneous Melanoma Patients (ACMP). This paper analyzes the evolution of ACMP who develop vitiligo during ICI treatment at Instituto Oncológico Henry Moore (IOHM). Methods: We selected all ACMP that received ICI between August 2015 and December 2019. We collected clinical data and compared Group A (ACMP with vitiligo) with Group B (ACMP without vitiligo) on: response rate (RR), time from ICI treatment initiation to progression (TTP) and overall survival (OS), defined as time from ICI treatment initiation to death. Outcomes were assessed using table tests and Kaplan-Meier curves with log-rank test. Results: Out of 32 ACMP treated with ICI, 12 Pt (37%) were in Group A and 20 Pt (63%) were in Group B. Table shows group characteristics and outcomes. Conclusions: 1) During treatment with ICI, 12 out of 32 (37%) advanced cutaneous melanoma patients were afflicted with vitiligo. 2) Two out of three patients who responded to ICI treatment developed vitiligo and obtained better TTP and OS than those without vitiligo. 3) According to these results, vitiligo is the consequence of the immune system reactivation responsible for considerable clinical benefits. Further studies should analyze if it is feasible to reduce ICI doses in patients who develop this adverse effect. 4) In this small and retrospective series, Nivolumab was more frequently correlated with vitiligo and clinical benefits, but we need prospective studies to decide which ICI treatment is the most effective.