PURPOSE: Laparoscopic appendectomy (LA) has become a gold standard for children even in complicated appendicitis. The purpose of this study was to compare the postoperative surgical site infection rates between laparoscopic and open appendectomy (OA) group in pediatric complicated appendicitis. METHODS: A total of 1,158 pediatric patients (age < or =15 years) underwent operation for appendicitis over a period of 8 years. Among these patients, 274 patients (23.7%) were diagnosed with complicated appendicitis by radiologic, operative and pathologic findings, and their clinical outcomes were retrospectively analyzed. RESULTS: Of the 274 patients with complicated appendicitis, 108 patients underwent LA and 166 patients underwent OA. Patients in the LA group returned to oral intake earlier (1.9 days vs. 2.7 days; p<0.01) and had a shorter hospital stay (5.0 days vs. 6.3 days; p<0.01). However, rate of postoperative intra-abdominal infection (organ/space surgical site infection) was higher in the LA group (LA 15/108 [13.9%] vs. OA 12/166 [7.2%]; p<0.01). Readmission rate was also higher in the LA group (LA 9/108 [8.3%] vs. OA 3/166 [1.8%]; p<0.01). CONCLUSION: The minimally invasive laparoscopic technique has more advantages compared to the open procedure in terms of hospital stay and early recovery. However, intra-abdominal infection and readmission rates were higher in the laparoscopy group. Further studies should be performed to evaluate high rate of organ/space surgical infection rate of laparoscopic procedure in pediatric complicated appendicitis.