Perianal and perineal pruritus is often associated with Enterobius vermicularis in children. Although this roundworm is common in pediatric practice, most doctors are unaware that it can cause appendicular colic with/or appendicitis, severe urogenital complications, bowel perforation, and peritonitis. We report a case of a young male who presented with signs and symptoms of acute peritonitis. Dur-ing the operation, perforation of the jejunum with a purulent exudate under the transverse colon, a left lateral canal, a Douglas cavity were found as well as single enlarged mesenteric lymph nodes. Histological studies detected Enterobius vermicularis in the lumen of the appendix and jejunum, as well as in the purulent exudate in the intestinal wall and serosa. A mesenteric lymph node, histologically presented with chronic nonspecific lymphadenitis. In conclusion, infection with Enterobius vermicularis should be considered in peri-tonitis, appendicitis, and enlarged mesenteric lymph nodes, especially in young patients.