Objective: This study was designed to determine whether postoperative adhesions to the peritoneum beneath the anterior abdominal wall incision could be decreased by peritoneal closure using less reactive suture material. Study Design: Six longitudinal abdominal incisions were made in each of 16 New Zealand white female rabbits. The peritoneum was randomly assigned to nonclosure or closure with chromic gut, braided nylon, braided coated polyglactin 910, polydioxanone monofilament, or poliglecaprone 25 suture. On postoperative day 14, adhesion formation was scored and evaluated microscopically. Results: Peritoneal closure decreased adhesion scores, compared with nonclosure, regardless of type of suture, and no particular suture was superior. Braided coated polyglactin 910 resulted in the least chronic inflammation and fibrosis. Conclusion: Peritoneal closure of peritoneum immediately below laparotomy incisions results in decreased adhesion scores, compared with nonclosure in our rabbit model. Adhesion formation could not be decreased further using less reactive suture. © 2007 Mosby, Inc. All rights reserved.