It has been shown recently that immunotherapy for advanced melanoma is effective. However, in order to improve the efficacy of immunotherapy, the identification of more specific melanoma-associated antigens is urgently needed. Kinesin family member 20A (KIF20A) has been reported to be a promising immunotherapeutic target for pancreatic cancer. To investigate the expression of KIF20A in melanoma, we performed quantitative reverse transcript (RT)-PCR and western blotting analyses of melanoma cell lines. We also investigated primary melanomas and naevus tissues with immunohistochemistry and real-time RT-PCR. KIF20A expression was detected in 59% of melanomas and 12% of naevi by immunohisto-chemistry, and 64% of melanomas and 60% of naevi by real-time RT-PCR. The primary melanomas that were positive for KIF20A showed a significantly greater thickness than those that were negative, and patients with KIF20A+ melanoma tended to develop recurrence earlier. These results suggest that immunotherapy with KIF20A may be a novel treatment option for advanced melanoma.