BACKGROUND: The authors investigated hernia repair rates following pedicled transverse rectus abdominis myocutaneous (TRAM), free TRAM, and deep inferior epigastric perforator (DIEP) flap breast reconstruction in English National Health Service hospitals. METHODS: Women diagnosed with breast cancer who underwent pedicled TRAM, free TRAM, or DIEP flap breast reconstruction procedures in English National Health Service hospitals between April of 2006 and March of 2012 were identified using the Hospital Episode Statistics database. Women who underwent mastectomy without reconstruction acted as controls, and hernia repair rates were calculated for all four groups. Multiple Cox regression was performed to estimate the relative risk of hernia repair among the reconstruction groups, adjusted for age, obesity, previous abdominal surgery, reconstruction year, and bilateral flap harvest. RESULTS: Between 2006 and 2012, 7929 women had a DIEP or TRAM flap breast reconstruction. The overall hernia repair rate within 3 years was 2.45 percent after abdominal flap breast reconstruction, and 0.28 percent among the 15,679 women who had mastectomy only. Mean time to hernia repair following an abdominal flap harvest was 17.7 months. Compared with DIEP flaps, free and pedicled TRAM flap procedures were associated with adjusted hazard ratios of 1.81 (95 percent CI, 1.24 to 2.64) and 2.89 (95 percent CI, 1.91 to 4.37), respectively. The only independent risk factor for hernia repair was age older than 60 years (p = 0.039). CONCLUSIONS: Abdominally based autologous breast reconstruction carries a small risk of subsequent donor-site hernia repair. The rates herein can be used to inform patients and to assess quality of care across service providers. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.