Malignant melanoma commonly occurs in skin and the incidences are uncommon. Especially, the incidences of subungual melanoma is less than 2% of total numbers of melanoma, and most of the cases tended to be misdiagnosed at first time. Thus, the prognoses are not good. We are going to report our experiences of subungual melanoma and diagnostic criteria in great toe initially misdiagnosed as ingrowing nail with a review of the literature.