Following a brief introduction regarding the epidemiology of diverticular disease, the authors report a rare case of diverticulitis of the cecum which had developed into an abscess. The patient was a 37-year-old man who was referred to the authors' attention with classic symptoms of acute appendicitis and it was therefore decided to operate. During laparotomy a small paracecal abscess involving a diverticulum with suppurating infection was found on the anterior wall of the cecum, whereas the appendix appeared to be completely unaffected. The diverticulum was removed together with a small area of the surrounding healthy tissue using a double-layer suture of the cecal wall. In the discussion the authors analyse the similarities and rarities of the case and compare it with national and international findings. Special attention is drawn to the problems of differential diagnosis raised by this rare pathology. In conclusion, the authors state that it is difficult to make a preoperative diagnosis and that therefore the decision to operate must be extemporary.