Background. To analyze the diagnosis and surgical treatment of acute appendicitis during pregnancy. Methods: The records of 24 pregnant patients who underwent surgery with preliminary diagnosis of acute appendicitis between January 1990 and July 2000 were reviewed retrospectively. Results: Between January 1990 and July 2000, there were 31,480 deliveries and the incidence of acute appendicitis was 1/1,312. Twenty patients had pathologically proven acute appendicitis (83.3%). Of the remaining 4 patients, one had hemorrhagic ovarian cyst, one had ovarian cyst rupture and in two cases no surgical pathology was diagnosed. Gestational stage at the diagnosis was first trimester in 7 patients, second trimester in 12 patients and third trimester in 5 patients. Five patients had abortions and premature delivery occurred in 2 patients. Conclusion: Diagnosis of acute appendicitis is difficult in pregnancy. Delay in diagnosis and surgery results in increase in complications. Emergency surgical intervention should be performed when acute appendicitis is suspected during pregnancy. Copyright (C) 2002 S. Karger AG, Basel.