Diverticulitis of the vermiform appendix is an often disregarded disease. Diagnosis follows after appendectomy due to inflammatory complications in the form of diverticulitis and appendicitis. Diverticula can also be found as a reason for complaints in histologically unaltered appendix or as an incidental finding. Diverticula of the vermiform appendix are classified as false (acquired) or true (congenital). We report on the case of a 57-year-old man with a perforated appendix diverticulum as reason for peritonitis and a paralytic ileus of the colon and small intestine.