Extramammary Paget's disease (EMPD) is a rare intraepidermal neoplastic disease. There is a well-known relationship between EMPD and underlying malignancy. However, only a few cases of EMPD and cutaneous melanoma have been reported previously. In this case report we present 2 cases of such double cancers: one as a collision tumor, the other at separate sites. We discuss the pathogenesis, treatment, and importance of a thorough clinical and radiological examination and review the literature.