Objective: Rectal strictures are a serious complication following operation for anorectal malformations (ARM). The purpose of this study was to determine the factors affecting rectal strictures following surgical treatments for ARM. Materials and Methods: Retrospective chart reviews of 204 patients with ARM who underwent surgical treatment at Siriraj Hospital between January 2003 and December 2019 were carried out. Results: Overall, the prevalence of post-operative rectal stricture was 19.6% (40/204). The higher types of ARM had higher rectal stricture rates. In low type ARM, the stricture rate following surgery for perineal fistula, vestibular fistula was 4.1% and 14.7%, respectively. Recto-bulbar urethral fistula and recto-prostatic urethral fistula had stricture rates of 19.2% and 26.7%, respectively, but in higher types, the stricture rates were above 70%. Complications such as wound infection, dehiscence, retraction, colonic necrosis and recurrent fistula all affected the post-operative stricture rate (p = 0.029, p = 0.01, p = 0.01, p = 0.042 and p = 0.002, respectively). The operation for low type ARM using local tissue flap, such as YV and cutback anoplasty, had low complications. More complicated operations were performed for higher type ARM. The higher the complication rate, the higher the post-operative rectal stricture. Routine rectal dilatation by parents seemed to prevent rectal strictures (p = 0.056). The surgical treatments for rectal strictures composed of 57.5% anoplasty, 17.5% PSARP, 15% abdo-assisted pull-through and 10% abdo-assisted PSARP. Conclusion: Post-operative rectal stricture occurred because of complications following complicated operations for high type ARM. A meticulous operative technique is crucial.