A subungual exostosis is an uncommon benign osteochondral lesion that appears as a painful nodule. Histologically, the tumors consist of a proliferating fibrocartilaginous cap that merged into mature trabecular bone at its base. From 1989 through 1991, 5 patients with subungual exostosis were treated. Three of them had exostosis on the great toe. There were three girls and two boys. The average age of the patients was 10.6 years. All of patients were treated by local excision. Two cases of our patients treated with an incomplete excision were recurred within 3 months after the original procedure. Lack of awareness of unusual lesion can cause initial misdiagnosis in many cases. We considered that a complete excision of the lesion is important for preventing the recurrence, and it should be confirmed with intraoperative radiographs.