BACKGROUND Postoperative bowel obstruction (PBO) plagues patients of all ages after intraabdominal surgery. We examined the incidence, risk factors, and the need for operative intervention of PBO. METHODS We reviewed all children who underwent a laparotomy or laparoscopy. Parameters included age, diagnosis, type and number of procedures, complications, time interval to PBO, treatment of PBO, morbidity, and mortality. RESULTS From 2001 to 2005, 2187 abdominal operations were performed. Overall, 61 patients (2.8%) developed a PBO; 43 (70.5%) required reoperation. Postoperative bowel obstruction was more common in patients younger than 1 year (28/601, 4.7%) compared with older children (33/1586, 2.1%; P = .01, beta = .80). In infants, PBO was not influenced by initial diagnosis (P = .26) or whether the initial operation was clean/clean-contaminated or contaminated/dirty (P = .12). In children older than 1 year, nonoperative treatment was more likely to be successful if PBO occurred within 12 weeks of initial operation (12/16 vs 3/14; P = .01). In contrast, all but one infant (16/17) with early PBO required reoperation. CONCLUSIONS The incidence of PBO is significantly higher in newborns and infants than in older children (who have rates comparable to those reported in adults). Infants are significantly more likely to require operative intervention, particularly if PBO occurs early after the initial operation.