Background Few large-scale epidemiologic studies evaluate the clinical and economic burden of appendicitis. These data may impact future research and treatment strategies. In this study, the objective was to determine the burden of appendectomy for appendicitis in terms of incidence rates, length of hospital stay (LOS) and hospital costs on a national level. In addition, outcomes were compared for subgroups based on surgical treatment, age and hospital setting. Methods Observational retrospective population-based cohort study using the national Dutch healthcare reimbursement registry, which covers hospital registration and reimbursement for 17 million inhabitants. Patients with a diagnosis of appendicitis who underwent appendectomy between 2006 and 2016 were included. Primary outcomes were incidence rates, LOS and hospital costs. Results A total of 135,025 patients were included. Some 53% of patients was male, and 64% was treated in a general hospital. The overall incidence rate of appendectomy was 81 per 100,000 inhabitants and showed a significant decreasing trend across time and age. Mean ± SD LOS per patient was 3.66 ± 3.5 days. LOS showed a significant increase with age and was significantly longer for open versus minimally invasive appendectomy. Mean ± SD hospital costs per patient were €3700 ± 1284. Costs were initially lower for open compared to minimally invasive appendectomy, but were similar from 2012 onward. Compared to non-university hospitals, patients treated in university hospitals had a significantly longer LOS and higher costs. Conclusions Appendectomy for appendicitis represents a substantial clinical and economic burden in the Netherlands. A preference for minimally invasive technique seems justified. Keywords Appendicitis • Appendectomy • Length of stay • Hospital costs Although acute appendicitis is highly prevalent among adults and children worldwide, literature on the clinical and economic burden of the disease is scarce. Emergent appendectomy remains the cornerstone of treatment and is nowadays mostly performed via the minimally invasive approach in Western countries [1-3]. It is known as a low-risk surgical procedure, with reported mortality rates between 0.03 and 0.24% [4-6]. Depending on the intraoperative classification, patients may be discharged within 24-48 h, or after a few days of prolonged antibiotic prophylaxis [7, 8]. Infectious complications occur in some 9-20% of patients, accompanied by a hospital readmission rate of 6% [5, 9]. Whereas morbidity and mortality are estimators of the burden of