strong correlation exists between obesity and breast cancer risk. 1 Obesity has also been shown to increase complications in abdominally based autologous breast reconstruction, leading to a denial of procedures for patients with obesity. 2,3 This concern for increased complications in patients with obesity may prompt clinicians to suggest bariatric surgery as a strategy to help these patients achieve weight loss in anticipation of breast reconstruction. 2,4 Given this Background: Massive weight loss (MWL) may have suboptimal effects on tissues used for autologous reconstruction. With the rising rates of obesity and bariatric surgery, more patients who have experienced MWL will be presenting for breast reconstruction. The authors hypothesize that autologous breast reconstruction in patients with a history of MWL will have more complications and require more revisions compared with reconstruction in patients without a history of MWL. Methods: A retrospective review was performed on patients who underwent autologous breast reconstruction by five microsurgeons at an academic institution from 2009 through 2020. Patients with a history of bariatric surgery or greater than 50-pound weight loss were identified and compared with patients who had not experienced MWL. Analysis compared demographics, operative details, complications, revision rates, and BREAST-Q scores. Results: Of 916 patients who underwent 1465 flaps, 39 patients with MWL (4.3%) underwent 68 flaps (4.6%), and 877 patients without MWL underwent 1397 flaps. MWL patients were more likely to require blood transfusions postoperatively (P = 0.005); experienced more surgical-site infections (P = 0.02), wound-healing complications of flap (P = 0.007) and donor sites (P = 0.03), and late partial flap losses (P = 0.03); and required more revisional surgery for flap (P = 0.009) and donor sites (P = 0.01). BREAST-Q scores were not statistically different for satisfaction with breasts or surgeon but were lower in MWL patients for psychosocial (P = 0.01) and sexual well-being (P = 0.04). Conclusions: Reconstructive surgeons should expect increased postoperative complications when performing autologous breast reconstruction in patients who have experienced MWL. These patients should be counseled on the possibility of an increased risk of postoperative complications and need for revisional surgery.