The benefit of laparoscopic (LA) versus open (OA) appendectomy, particularly for complicated appendicitis, remains unclear. Our objectives were to assess 30-day outcomes after LA versus OA for acute appendicitis and complicated appendicitis, determine the incidence of specific outcomes after appendectomy, and examine factors influencing the utilization and duration of the operative approach with multi-institutional clinical data. Using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database (2005-2008), patients were identified who underwent emergency appendectomy for acute appendicitis at 222 participating hospitals. Regression models, which included propensity score adjustment to minimize the influence of treatment selection bias, were constructed. Models assessed the association between surgical approach (LA vs OA) and risk-adjusted overall morbidity, surgical site infection (SSI), serious morbidity, and serious morbidity/mortality, as well as individual complications in patients with acute appendicitis and complicated appendicitis. The relationships between operative approach, operative duration, and extended duration of stay with hospital academic affiliation were also examined. Of 32,683 patients, 24,969 (76.4%) underwent LA and 7,714 (23.6%) underwent OA. Patients who underwent OA were significantly older with more comorbidities compared with those who underwent LA. Patients treated with LA were less likely to experience an overall morbidity (4.5% vs 8.8%; odds ratio [OR], 0.60; 95% confidence interval [CI], 0.54-0.68) or a SSI (3.3% vs 6.7%; OR, 0.57; 95% CI, 0.50-0.65) but not a serious morbidity (2.6% vs 4.2%; OR, 0.86; 95% CI, 0.74-1.01) or a serious morbidity/mortality (2.6% vs 4.3%; OR, 0.87; 95% CI, 0.74-1.01) compared with those who underwent OA. All patients treated with LA were significantly less likely to develop individual infectious complications except for organ space SSI. Among patients with complicated appendicitis, organ space SSI was significantly more common after laparoscopic appendectomy (6.3% vs 4.8%; OR, 1.35; 95% CI, 1.05-1.73). For all patients with acute appendicitis, those treated at academic-affiliated versus community hospitals were equally likely to undergo LA versus OA (77.0% vs 77.3%; P = .58). Operative duration at academic centers was significantly longer for both LA and OA (LA, 47 vs 38 minutes [P < .0001]; OA, 49 vs 44 minutes [P < .0001]). Median duration of stay after LA was 1 day at both academic-affiliated and community hospitals. Within ACS NSQIP hospitals, LA is associated with lower overall morbidity in selected patients. However, patients with complicated appendicitis may have a greater risk of organ space SSI after LA. Academic affiliation does not seem to influence the operative approach. However, LA is associated with similar durations of stay but slightly greater operative times than OA at academic versus community hospitals. Copyright © 2010 Mosby, Inc. All rights reserved.