Depression is a common problem among patients awaiting organ transplantation, but little is known about the impact of depression and its treatment on the outcomes of liver transplantation. In this retrospective cohort analysis, we studied all patients over 18 years of age who underwent liver transplantation during a 5-year period (2004-2008) at a single center. Among 179 recipients, 65 patients had depression, as defined by a health care provider assessment, before transplantation. Depression was defined as past or active depression or an adjustment disorder. The associations between pretransplant depression and various outcomes (time to death, graft failure, first acute cellular rejection episode, first infection, and first rehospitalization) were assessed. In the entire sample, more patients with depression required posttransplant psychiatric care (37% versus 18%); the adjusted hazard ratio was 2. 28 (1.27-4.11). The rates of other outcomes, including hospital readmission, acute cellular rejection, graft failure, mortality, and infection, were similar for patients with depression and patients without depression. Among those with depression, patients on antidepressants at the time of transplantation had acute cellular rejection less frequently than those not taking antidepressants (13% versus 40%); the adjusted hazard ratio was 0.14 (0.03-0.62). The rates of other outcomes were similar between these 2 groups. These data indicate that depression affects posttransplant psychiatric morbidity but not other medical outcomes of liver transplantation. Pharmacological treatment of depression may significantly reduce the incidence of acute cellular rejection in patients undergoing liver transplantation. However, future prospective studies of mental health and liver transplantation are required to definitively assess the effects of antidepressant medications on medical outcomes.