Please use this link to access this publication. Abstract Background There is an increasing prevalence of marijuana use in the general population yet clinical studies on marijuana's effect on surgical outcomes remain limited. Marijuana's effect on wound healing, venous thromboembolism (VTE) due to endothelial inflammation, and bleeding due to inhibited platelet function have been cited based on animal models but have not been evaluated clinically in patients undergoing microsurgical reconstruction. Methods Retrospective chart review was performed on all patients who underwent abdominal-based free flap breast reconstruction in a single institute from August 2018 to December 2022. Patient self-reported marijuana use, demographics, total narcotic use during hospitalization...