Situs inversus totalis (SIT) is a rare disease in which there is transposition of thoracic and abdominal organs. The symptoms of appendicitis in SIT are often confused with other intraperitoneal processes such as diverticulitis. We report the case of a 65-year-old, attended by emergency epigastric pain of 20 hours of the onset after a few hours left iliac fosse migrates associated with hyporexia. Diverticulitis is diagnosed in the first instance, and after the respective imaging tests is discarded for being relevant findings with situs inversus totalis and left poses appendicitis. Therefore, the realization of an adequate medical history and physical examination supported by imaging tests are important to keep in mind, appendicitis as part of the differential diagnosis, in order to avoid errors in diagnosis and treatment.