Patients who are suspected of having acute appendicitis usually undergo surgery in order to avoid life-threatening complications such as perforation and peritonitis. However, acute appendicitis is difficult to distinguish from other sources of right-sided abdominal pain. The clinical picture is almost indistinguishable from appendiceal diverticulitis, which is a rare entity and remains a difficult diagnostic problem.We describe the case of a 39-year-old male with perforated appendiceal diverticulitis. The patient was admitted to our surgical unit with acute appendicitis-like symptoms and underwent surgery with a diagnosis of suspected acute appendicitis.The patient was found to have perforated appendiceal diverticulitis and standard appendectomy with abdominal lavage was carried out.Most patients presenting with acute right-sided peritonitic pain are diagnosed and managed as cases of acute appendicitis. Acute pain in the lower right side of the abdomen caused by appendiceal diverticulitis is very rare and clinically indistinguishable from acute appendicitis. Inflammatory complications of appendiceal diverticula mimic acute appendicitis.Every surgeon should be aware of the possibility of diverticulitis of the appendix in the operating room, even if this does not change the operative management. As diverticula of the cecum can be found as solitary lesions, as multiple lesions confined to the right colon, or as part of a generalized disease of the entire colon, postoperative barium enema examination may be useful.