Endometriosis is a well known cause of infertility. Endometriosis of the appendix is a very rare condition. To highlight this rare entity, we are reporting a case of a young lady who was admitted with recurrent attacks of lower abdominal pain associated with primary infertility. Preoperative diagnosis was acute appendicitis. Histopathological examination of the appendix revealed endometriosis. Endometriosis should be considered in the differential diagnosis of recurrent lower abdominal pain in young females especially with history of infertility.