Damage to the intercostal nerves during deep inferior epigastric perforator (DIEP) and muscle-sparing free transverse rectus abdominis musculocutaneous (TRAM) flap harvest compromises abdominal wall integrity. Intercostal motor nerves are closely associated with the lateral branch of the deep inferior epigastric artery (DIEA); therefore, the authors hypothesized that medial branch flap donor sites would develop fewer abdominal bulges/hernias. The authors evaluated 2043 consecutive abdomen-based free flap breast reconstructions performed at The University of Texas M. D. Anderson Cancer Center between 2000 and 2010. Of these, the authors included only DIEP or muscle-sparing free TRAM flaps in which it could be clearly determined from which branch perforators were harvested. The authors examined the relationship between patient and treatment factors and donor-site hernia and bulge. The authors included 501 patients with a mean follow-up of 31 months [289 medial branch flaps (47 percent) and 326 lateral branch flaps (53 percent)]. Patient demographics, reconstruction timing, DIEP versus muscle-sparing free TRAM, unilateral versus bilateral distribution, and percentage of mesh closures were similar between the branch harvest groups. Twenty-eight donor sites (4.6 percent) developed a bulge/hernia. Abdominal bulge/hernia rates were similar between the medial and lateral branch donor sites (3.5 percent and 5.5 percent, respectively) (p = 0.20). This is the largest study to date comparing donor-site morbidity following medial or lateral DIEA branch harvest. Choice of perforators should be based on quality, size, and orientation. Medial versus lateral row perforators should not be harvested preferentially to reduce donor-site hernia or bulge.