['Children with perforated appendicitis have a relatively high risk of intra-abdominal abscesses. There is no evidence that prolonged antibiotic treatment after surgery reduces intra-abdominal abscess formation. We compared two patient groups with perforated appendicitis with different postoperative antibiotic treatment protocols.', 'We retrospectively reviewed patients younger than age 18\xa0years who underwent appendectomy for perforated appendicitis at two academic hospitals between January 1992 and December 2006. Perforation was diagnosed during surgery and confirmed during histopathological evaluation. Patients in hospital A received 5\xa0days of antibiotics postoperatively, unless decided otherwise on clinical grounds. Patients in hospital B received antibiotics for 5\xa0days, continued until serum C-reactive protein (CRP) was <20\xa0mg/l. Univariate logistic regression analysis was performed on intention-to-treat basis. p\xa0<\xa00.05 was considered significant.', 'A total of 149 children underwent appendectomy for perforated appendicitis: 68 in hospital A, and 81 in hospital B. As expected, the median (range) use of antibiotics was significantly different: 5 (range, 1-16) and 7 (range, 2-32) days, respectively (p\xa0<\xa00.0001). However, the incidence of postoperative intra-abdominal abscesses was similar (p\xa0=\xa00.95). Regression analysis demonstrated that sex (female) was a risk factor for abscess formation, whereas surgical technique and young age were not.'] Does prolonged antibiotic treatment prevent intra-abdominal abscesses in perforated appendicitis?