The authors describe an unusual case of an 11-year-old girl who had right lower quadrant pain due to unilateral salpingitis, suppurative omentitis and periappendicitis. The etiologic agent was the parasite Enterobius vermicularis. A review of the literature revealed that pinworm may be the cause not only of appendicitis, but of inflammatory reactions in other intra-abdominal sites and that the frequency of this occurrence is probably higher than has previously been suspected.