Endometriosis is a relatively common disorder in women of reproductive age; however, appendiceal endometriosis is rare. Thus, a definitive diagnosis is likely to be established only by histology of the appendix. We report a case of endometriosis of the appendix in a 42-year-old woman who presented with symptoms of acute appendicitis. We treated the patient by performing laparoscopic appendectomy, which resulted in a good outcome.