BACKGROUND: Although the feasibility of laparoscopic appendectomy (LA) in complicated appendicitis (CA) has been demonstrated, LA is typically underused in CA due to its high conversion rate. However, little is known regarding the clinical course of conversion in CA. MATERIALS AND METHODS: Between January 2005 and April 2012, 1699 patients older than 16 years underwent an appendectomy at our institution. Of these, 207 were confirmed to have CA, which was defined as operative findings of gangrenous or perforated appendix, with or without abscess formation. Patients were divided into the following three groups: open group (OG), laparoscopy group (LG), and converted group (CG). Perioperative outcomes were compared between the three groups. RESULTS: Thirty-eight patients underwent open surgery. Among the 169 patients for whom laparoscopic surgery was originally attempted, 20 (11.8%) were converted. Operation time was significantly longer and estimated blood loss was higher in the CG than in the other groups. Fewer overall complications were observed and the length of hospital stay (LOH) was shorter in the LG than in the OG and CG. However, no significant differences were observed between the OG and CG regarding the overall complication rate or LOH. Operation method was the only factor associated with postoperative morbidity in multivariate analysis. CONCLUSION: While completion by laparoscopy was associated with better outcomes than the other two procedures at all levels, open conversion did not increase the overall morbidity or LOH compared with open appendectomy. Laparoscopic approach could be a viable option even in the management of CA.