Background. Exercise training is effective in improving the cardiovascular risk profiles of nontransplanted patients, but the health benefits and potential harms of routine exercise training after solid organ transplantation are unclear. This study aims to assess the health benefits and harms of supervised exercise training programs in solid organ recipients. Methods. We systematically reviewed all randomized controlled trials (RCTs) comparing the outcomes of exercise training programs in solid organ recipients against standard care. MEDLINE, EMBASE, the Transplant Library from the Centre for Evidence in Transplantation, and the Cochrane Central Register of Controlled Trials were searched to June 2012. Results. In total, 15 eligible RCTs involving 643 patients (9 cardiac transplants [n=250 patients], 2 kidney transplants [n=164 patients], 3 lung transplants [n=110 patients], and 1 liver transplant [n=119 patients]) were included. Cardiac transplant recipients who engaged in an exercise program after transplantation showed significant improvement in maximal oxygen uptake (standardized mean difference, 0.77; 95% confidence interval, 0.10Y1.45) but no improvement in the overall serum lipid profile, blood pressure, and glycemic control compared with standard care. Among other solid organ transplant recipients, no significant improvements in exercise capacity or cardiovascular risk factors such as incidence of new-onset diabetes after transplantation were observed, but all effect estimates were very imprecise. Conclusions. Exercise training is a promising but unproven intervention for improving the cardiovascular outcomes of solid organ transplant recipients. Existing trials are small, of relatively short duration, and focused on surrogate outcomes. Large-scale RCTs are urgently required if resources are to be directed toward exercise programs.