Small-bowel obstruction secondary to internal hernia is a known postoperative complication of laparoscopic Roux-en-Y gastric bypass (RYGBP). Petersen's defect is the most common site of postoperative internal herniation. The authors describe their technique of closure of the infracolic component of the Petersen's defect using continuous non-absorbable suture material. The method has been used successfully to reduce the incidence of internal herniation after laparoscopic RYGBP.