Four cases of subungal exostosis are presented. All of them were young male and big toe was involved in 2 cases. Histological features of subungal exostosis was characteristic; the cancellous bony stalk was capped mainly fibrocartilage, although scattered areas of hyaline cartilage were also found where enchondal ossification occured. Superficial to this cartilaginous cap, there was fibrous tisse covering. When terminal phalax of a toe shows deformity of nail and skin changes due to hard mass, radiological examination is required for the proper diagnosis and treatment. Complete local excision is required but damage to the nail bed during excision should be avoided.