Background: Acute appendicitis is the most common cause of non-obstetric surgical disease in pregnant women. The diagnosis and treatment of appendicitis during pregnancy are very important because it can cause life-threatening morbidity to the fetus and mother. We evaluated the clinical characteristics of acute appendicitis in pregnant women. Methods: We retrospectively reviewed a medical database that included patients who underwent surgery for acute appendicitis at our hospital from January 2013 through December 2022. We compared non-pregnant women of reproductive age with pregnant women. We classified the pregnant women according to gestational age. Result: A total of 828 patients were reproductive-aged women between 15 and 44 years old. There were 759 non-pregnant patients and 69 pregnant patients. ASA (American Society of Anesthesiologists) physical status classes were significantly higher and hospital stays were significantly longer in the pregnant group. There was no significant intergroup difference in terms of the proportions of complicated appendicitis, extended surgery, or complications. When the enrolled pregnant women were divided into three subgroups according to gestational age, the mean operation time was longest in the third-trimester subgroup. There were no differences among the subgroups in terms of the proportions of complicated appendicitis, extended surgery, or complications, nor were there differences among the subgroups in terms of laboratory findings. Preterm labor and stillbirth occurred in two pregnant women with complicated appendicitis in the second trimester. Conclusion: Immediate surgical treatment should be strongly considered in pregnant women with appendicitis. Efforts for more accurate diagnosis are needed for pregnant women with appendicitis.