BACKGROUND: The novel coronavirus disease 2019 (COVID-19) has resulted in major changes in health-care systems and emer- gency surgical interventions. Here, we examined patients with acute appendicitis who presented to emergency departments and com- pared diagnosis, treatment, and post-treatment processes before and during the pandemic period and investigated how the pandemic affected management of acute appendicitis. METHODS: A national, multicenter, and cohort study model was designed that included patients older than 18 years of age diag- nosed with acute appendicitis clinically and/or radiologically, with patients compared before (pre-pandemic period: January 1–April 30, 2019) and after (pandemic period: January 1–April 30, 2020) the pandemic. Our investigation included comparisons of pre-operative imaging methods, presence of plastron appendicitis/abscess, conservative/surgical approach, type of anesthesia given, laparoscopic/ open surgical approach, bowel resection rates, drain insertion rates, and presence of post-operative complications RESULTS: For the two study groups, 8972 patients from 69 centers were examined, with 4582 patients operated in the pre-pan- demic period and 4234 patients operated in the pandemic period. During the pandemic period, 63.6% of patients underwent open surgery, whereas 34.4% had laparoscopic surgery. Although 60 patients (1.3%) requested non-operative follow-up in the pre-pandemic period, 94 patients (2.2%) requested this in the pandemic period. When conditions of patients were evaluated regardless of their own wishes, 114 patients (2.4%) before and 163 patients (3.8%) during the pandemic received non-operative follow-up. CONCLUSION: Our study did not show the direct correlation between the application of COVID-19-related restrictions and the severity of acute appendicitis. Although non-operative management rates have been increased during the COVID-19 period, the incidences of both complicated and the uncomplicated appendicitis were similar during the COVID-19 crisis period. Given this infor- mation non-operative management can be employed for patients diagnosed with appendicitis.