Background: Allograft dysfunction due to presumed antibody-mediated rejection (pAMR) is one of the most serious complications of heart transplantation. Combination therapies of high-dose steroids, intravenous immune globulin, and/or therapeutic plasma exchange (TPE) are often used in this setting. Methods: We performed a 9-year retrospective review of all episodes of pAMR treated with TPE at our institution. pAMR diagnosis was based on clinical and pathologic findings. Left ventricular ejection fraction (LVEF) was measured at baseline, prior to initiation of TPE, and during the course of treatment. Results: There were 42 patients with 47 episodes of pAMR treated with TPE. The majority of episodes were treated with three TPE; however, eight required only two TPE and five episodes required 3 TPE. All episodes of pAMR had LVEF measured before and after the series of TPEs. The mean pre-TPE LVEF was 38% compared with a post-therapy mean LVEF of 50% (P0.0001). In 16 episodes of pAMR, for which LVEF was measured following each apheresis, there was significant improvement of allograft function after the first TPE (pre-TPE mean LVEF of 31% and post-first TPE mean LVEF of 37%; P50.02). Incremental and significant improvement in allograft function continued following each TPE. Changes in human leukocyte antigen-donor specific antibodies and fibrinogen did not correlate with ejection fraction response. Conclusions: The rapid improvement in allograft function in our patients is most likely due to TPE as other pharmacologic interventions have longer onset. TPE should be considered a first-line intervention in the setting of pAMR.