Subungual exostosis is a benign osteocartilaginous tumor of the ungual apparatus, particularly of the toes. It affects both sexes equally, more frequently in the second and third decades of life. We describe a 6-year-old girl who came to our attention because of the enlargement of a pinkish nodule in the distal part of the nail bed of the first toe, progressively elevating the nail plate. History, X-ray imaging and histopathologic examination led us to confirm our clinical suspicion, excluding any other possible cause of the subungual mass. The peculiar features of this clinical entity, and the possibility of effective treatment by practical surgical techniques, are discussed.