Purpose: Obstetric anal sphincter injury is one of the most common complications during delivery. Simulation models with manikins can be used as an effective medical learning method to improve students’ abilities before encountering patients. The present study aimed to describe the development of an anal sphincter injury model and to assess residents’ satisfaction and self-confidence after a perineal repair workshop with an anal sphincter injury simulator in Indonesia. Methods: This was a cross-sectional study with evaluation of outcomes before and after the workshop. We created a silicone-latex simulation anal sphincter injury model. Then, we validated this simulation and used it as a simulation model for the workshop. We asked residents about their satisfaction with repairing anal sphincter injuries using a simulation model and residents’ self-confidence when practicing anal sphincter injury repair. Results: All residents felt the simulation-based workshop was valuable (100%). Most of the scores for the similarity of the simulation model were good (about 8 out of maximum 10). The self-assessment of confidence was measured before and after the workshop. Overall self-confidence increased significantly after the workshop in identifying the external sphincter ani (EAS) (P=0.031), suturing the anal mucosa (P=0.001), suturing the internal sphincter ani (P=0.001), suturing the EAS (P<0.001), and evaluating the sphincter ani tone (P=0.016). Conclusion The anal sphincter injury simulator improved residents’ self-confidence in identifying the EAS, suturing the anal mucosa, suturing the internal sphincter ani, suturing the EAS, and evaluating sphincter ani tone.