OBJECTIVE:: To treat anal incontinence due to obstetric external anal sphincter disruption via injection of autologous myoblast cells. DESIGN:: Observational pilot study. SETTING:: University hospital and district hospital PATIENTS:: 10 women suffering from anal incontinence due to obstetric anal sphincter injury, refractory to conventional non-surgical therapy. INTERVENTIONS:: Autologous myoblasts were cultured from a pectoralis muscle biopsy, harvested, and injected into the external anal sphincter defect using direct ultrasound guidance. MAIN OUTCOME MEASURES:: Wexner incontinence score, anal squeeze pressures, and quality of life 12 months after injection. Safety and technical feasibility. RESULTS:: The procedure was well tolerated and no adverse events were observed. At 12 months the Wexner incontince score had decreased by a mean of 13.7 units (95% CI, −16.3 to −11.2), anal squeeze pressures were unchanged, and overall quality of life scores improved by a median of 30 points (95% CI, 25 to 42). Anal squeeze pressures did rise significantly at 1 month and 6 months post-injection (p = 0.03). CONCLUSIONS:: Injection of autologous myoblasts is safe, well tolerated, and significantly improves symptoms of anal incontinence due to obstetric anal sphincter trauma.