Objective: To determine the effects of pregnancy on the presentation, management, surgical and obstetrics outcome of patients with acute appendicitis.Methods: This prospective cohort study was conducted during a 2-year period from 2014 to 2016 in Shahid Faghihi hospital of Shiraz University of Medical Sciences. We enrolled all the pregnant individuals with acute appendicitis who required surgical appendectomy. We also enrolled age-matched controls of non-pregnant women undergoing open appendectomy during the study period. The presentation, clinical and laboratory characteristics, surgical and obstetrics outcomes were determined in both study groups and were further compared between them. In order to determine the determinants of outcome, we also ran a multivariate logistic regression model.Results: Overall we included a total number of 584 patients with presumed appendicitis among whom there were 58 (9.94%) and 526 (90.06%) non-pregnant individuals. The pregnant patients had significantly longer duration of symptoms (p=0.038), lower temperature (p=0.026), longer duration of hospital stay (p=0.026) and higher rate of hospital admission longer than 2 days (p=0.031). The complications of the surgical procedure were comparable between the two study groups except for the pneumonia which was significantly higher in pregnant patient (p=0.041). After adjusting for confounders such as age and ethnicity, pregnancy remained significantly associated with lower temperature (p=0.018), longer symptom duration (p=0.042) and higher rate of pneumonia (p=0.049).Conclusion: Acute appendicitis during the pregnancy was associated with longer duration of symptoms, lower body temperature and higher rate of pneumonia. The pregnancy and neonatal outcomes were comparable to the previously reported data.