INTRODUCTION A subungual exostosis (SE) is a bony overgrowth that is permanently attached to the tip of the distal phalanx. Its pathology differs from osteocartilaginous exostoses in that it mainly involves the overgrowth of normal bone, which may present beneath the toenail or on the sides of the toe. This retrospective study aimed to report the results of surgical treatment when the diagnosis of SE was delayed; the condition was initially considered to be another pathology affecting a different nail or the terminal toe. METHODS A total of 17 patients (12 female, five male) were included in the study. All surgical resections were performed by the same surgeon using the same surgical technique, with the patient under digital anaesthesia. The patients were evaluated pre- and postoperatively (on Weeks 1 and 6, the first year, and the last follow-up visit) using the American Orthopaedic Foot and Ankle Society questionnaire and the Visual Analogue Scale score. RESULTS The patients underwent surgery for SE removal between December 2009 and October 2012. Their mean age was 21.3 ± 4.4 (range 14–29) years and the mean follow-up period was 27.1 ± 7.8 (range 18–45) months. Clinical or radiological recurrence was not observed in any of the patients during the follow-up period. Four patients had superficial infections, which were treated using appropriate antibiotic therapies. CONCLUSION As SE is an uncommon benign lesion, its diagnosis may be delayed. Radiography may be useful in obtaining a differential diagnosis.