Infestation with Enterobius vermicularis is the most frequent worm infection in man. As the infestation is seldom manifested otherwise than by pruritus ani, we want to describe a case where the disease picture was quite different and presented rare clinical symptoms without pruritus ani. In a 13-year-old boy with increasing tenderness at McBurney's point, appendectomy was performed. Except for elevated total IgE and blood eosinophil count, no abnormal values were demonstrated, and all relevant tests were negative. The histopathological examination showed the appendiceal lumen filled with feces containing Enterobius vermicularis. An anal cellophane test performed five weeks later revealed no pinworm ova.