The problem of diagnostics and treatment of acute abdomen in pregnant patients is still remains a very important issue, as unfavorable results of treatment lead to increase in maternal and perinatal mortality. Atypical localization of appendix plays crucial role in development of complications of acute appendicitis. Here we present a clinical case of a pregnant patient with performed diagnostic laparoscopy, which was followed by unrecognized eventration of the appendix to the subcutaneous fat in the right inguinal region and acute appendicitis at 27-28 weeks of gestation. We suppose that key to effective treatment of acute appendicitis in pregnant patients is early diagnosis.