An isolated ileal perforation is presented in a 12-yr-old patient. Microscopic examination revealed granulomatous inflammation due to Enterobius vermicularis (pinworm). This is only the third documented report of intestinal perforation involving pinworms. Although infestation with this parasite is generally considered to be relatively harmless, on rare occasions, it can be a significant cause of morbidity due to its potential ability to invade the tissues.