['The aim of this study was to determine if the placement of prophylactic drains influences the incidence of postoperative adverse events in neonates.', 'Neonatal patients undergoing laparotomy between April 2000 and December 2007 were prospectively assigned to aggressive peritoneal cavity lavage, without the placement of prophylactic drains, before abdominal closure (non-drainage group, n = 111). The historical control group consisted of neonates who underwent laparotomy with routine prophylactic drain placement between January 1993 and March 2000 (drainage group, n = 87). The incidence of postoperative adverse events was compared between the two groups.', 'There were no significant differences in the incidence of overall complications (drainage, 48%; non-drainage, 36%: p = 0.08), infectious complications (drainage, 34%; non-drainage, 26%: p = 0.20) or surgical site infections (drainage, 20%; non-drainage, 14%: p = 0.25) between the two groups. In the subgroup analysis, the incidences of total postoperative complications and infectious complications were significantly higher in the drainage group compared with the non-drainage group for upper gastrointestinal tract operations (52 vs. 20%; 39 vs. 6.7%) (p = 0.04 and 0.02, respectively).'] Does placement of prophylactic drain after laparotomy may increase infectious complications in neonates?