Subungual exostosis is a slow‐growing, benign outgrowth of normal bone or calcified cartilaginous remains of the distal phalanx. Complete surgical excision of lesions, including the cartilaginous cap, is a unique curative method. An 18‐year‐old male presented with a protruding papule on the right great toenail. Diagnosis of subungual exostosis had been established and complete excision was performed. In addition, an in situ thin split‐thickness toenail bed graft was used to cover the defect. At 6 months after excision, the patient had no complaint of recurrence or pain. We report on a unique trial case of subungual exostosis treated with thin split‐thickness nail bed grafts taken from the adjacent normal nail bed of the affected toe.