BACKGROUND An increasing number of HIV-infected children require a surgical procedure. The aim of this study was to investigate factors associated with the development of complications in HIV-infected children undergoing surgery. METHODS A prospective study of HIV-infected children younger than 60 months undergoing surgery at a tertiary referral pediatric hospital from July 2004 to July 2008 was performed. Children were followed postoperatively for the development of complications, length of stay, and mortality. RESULTS Eighty-two HIV-infected children, with a median age of 11.5 months (interquartile range, 6-24 months), were enrolled. Most (68; 82.9%) had World Health Organization stage 3 or 4 HIV disease, 72 (88%) had Centers for Disease Control and Prevention stage 2 or 3 disease, and 60 (73%) were taking highly active antiretroviral therapy. Half (41; 50%) were underweight, 37 (45.1%) underwent emergency surgery, 28 (34.2%) required major surgery, and 40 (48.7%) had surgical site contamination at the time of surgery. The median length of hospital stay was 4 days (interquartile range, 2-14 days), and in-hospital mortality was 6 (7%). Thirty-four (42%) children developed 37 complications. On univariate analysis, malnutrition, HIV stage, or type of surgery was not associated with development of complications. In contrast, young age (6 vs 13.5 months; P = .0004), low hemoglobin (9.6 vs 10.5 g/dL; P = .04), or having a major procedure (14 [42%] vs 9 [18%]; P = .03; relative risk, 2.2 [1.2-4.8]) was associated with complications. On logistic regression, younger age (odds ratio = 4.3; P = .004; 95% confidence interval, 1.6-11.9) and major surgery (odds ratio = 6.8; P = .001; 95% confidence interval, 1.5-31.4) were associated with development of a complication. CONCLUSIONS Young age and major surgery were the main predicators of complications in HIV-infected children undergoing surgery.