Subungual exostosis is a benign, acquired tumor of cartilaginous bone which occurs beneath the nail of the distal phalanx, and can often lead to displacement and deformity of the overlying nail. Complete surgical excision is a curative treatment for subungual exostosis. Since there have been no case reports of complete surgical removal of subungual exostosis in the Korean dermatologic literature, we report four cases of subungual exostosis that were successfully treated through complete excision or excision in combination with additional curettage.