Background: Ipilimumab and tremelimumab are human monoclonal antibodies against cytotoxic T-lymphocyte antigen-4 (CTLA-4). Ipilimumab was the first agent to show a statistically significant benefit in overall survival with durable-long-term responses for advanced melanoma patients both in first-and second-line setting. Up to date, there is no proven association between the BRAF-V600E mutation and the disease control rate (DCR) in response to Ipilimumab. Moreover, significantly shorter survival rates have been reported in patients harboring an NRAS mutation than in those without. This retrospective analysis was carried out to assess if BRAF (V600) and NRAS mutation status affects the clinical outcome of Ipilimumab-treated melanoma patients. Methods: This is a retrospective multi-center analysisof 71 patients, with confirmed BRAF and NRAS mutation status, treated with anti-CTLA-4 antibodies from December 2006 until August 2012. The cut-off for the estimation of overall survival was end of November 2012. Results: The median overall survival of BRAFV600/NRAS mutant patients (n=44) was 1,41 years compared with 2.67 years in BRAF/NRAS wild-type patients (n=27). Although this difference was not statistically significant there was a trend for improved survival in wild-type patients. Of the 71 patients analyzed, 56 received chemotherapy prior to Ipilimumab. In the BRAF/NRAS mutant cohort, 12 patients received Ipilimumab following either a BRAF- or a MEK- inhibitor. Of those 12 patients, 8 progressed and were unable to complete Ipilimumab. Of the 4 patients who completed 4 cycles of Ipilimumab, 2 were subsequently treated with a BRAF inhibitor. Furthermore out of the 71 patients, 8 patients received a BRAF or a MEK inhibitor after progression; 5 of them are still alive. Conclusions: This is the first retrospective study to evaluate the association of both BRAF and NRAS mutational status with the overall survival of Ipilimumab-treated patients. There was a trend towards an improved survival in the BRAF/NRAS wild-type subpopulation. Additional patients will be examined to foster these preliminary results.