Objective To evaluate the effect of combined acupuncture anesthesia on the risk of postoperative urinary retention (POUR) in patients after anal surgery based on real-world data, so as to provide evidence-based basis for optimal anesthesia method for anal surgery. Methods The data of patients undergoing anal surgery from Jan. 1, 2012 to Dec. 31, 2018 were retrospectively collected from the electronic medical records (EMR) system of Shuguang Hospital, Shanghai University of Traditional Chinese Medicine. The information of gender, age, length of hospital stay, anesthesia method and International Classification of Diseases, Ninth Revision, Clinical Modification Volume 3 (ICD-9-CM3) codes were extracted. Ascertainment of POUR was based on the medical order of indwelled catheterization and the charge of catheter. For cases with intraoperative anesthesia change, final anesthesia method was recorded. Results A total of 11 440 patients undergoing anorectal surgery were enrolled with an age of 39 (32, 51) years and a male to female ratio of 1.94:1. Among them, 6 083 cases (53.2%) were treated with combined acupuncture anesthesia, 3 392 cases (29.7%) with posterior perineal nerve block anesthesia, 1 420 (12.4%) cases with intravenous anesthesia, 408 (3.6%) cases with local anesthesia, 65 (0.6%) cases with spinal anesthesia, 46 (0.4%) cases with general anesthesia, and 26 (0.2%) cases with other anesthesia methods. The incidence of POUR was 3.5% (395 cases). Univariate logistic regression analysis showed that age ≥ 60 years (odds ratio[OR]=1.76, 95% confidence interval[CI]1.36-2.27, P<0.001) and female (OR=1.36, 95% CI 1.11-1.67, P=0.003) were risk factors for POUR in patients undergoing anal surgery. Multivariate logistic regression analysis showed that compared with combined acupuncture anesthesia, posterior perineal nerve block anesthesia, intravenous anesthesia and spinal anesthesia were significantly associated with increased risk of POUR (posterior perineal nerve block anesthesia:OR=1.42, 95% CI 1.13-1.78, P=0.002; intravenous anesthesia:OR=1.48, 95% CI 1.10-1.99, P=0.009; spinal anesthesia:OR=2.75, 95% CI 1.09-6.93, P=0.032). Multivariate logistic regression analysis was performed after adjusting for gender, age and disease diagnosis, and showed the similar results (posterior perineal nerve block anesthesia:adjusted OR=1.33, 95% CI 1.06-1.67, P=0.014; intravenous anesthesia:adjusted OR=1.43, 95% CI 1.06-1.92, P=0.019; and spinal anesthesia:adjusted OR=4.93, 95% CI 1.92-12.67, P=0.001). Subgroup analysis showed that compared with posterior perineal nerve block anesthesia, combined acupuncture anesthesia could reduce the risk of POUR by 41% in female patients (OR=0.59, 95% CI 0.42-0.84, P=0.003) and 30% in patients <60 years (OR=0.70, 95% CI 0.54-0.90, P=0.006). Conclusion Age ≥ 60 years and female sex are risk factors of POUR in patients undergoing anal surgery. Combined acupuncture anesthesia is helpful to reduce the risk of POUR after anal surgery.