Traditional Chinese medication (TCM) is increasingly used to treat cardiovascular disease (CVD) in China and some other Asian countries. However, therapeutic efficacy and adverse effects of TCM are difficult to evaluate because few large-scale, randomized controlled trials (RCTs) enrolling patients with CVD have been performed. In this Review, we critically examine the current evidence on the cardiovascular effects of TCM. We reviewed 68 RCTs that included a total of 16,171 patients. The methodological quality of the trials was generally low. Only three reports described adverse cardiovascular events specifically, although in most studies TCM was associated with significant improvements in surrogate end points for hypertension, coronary heart disease, cardiac arrhythmias, and heart failure. The risk of adverse effects was not increased compared with no intervention, placebo, or Western medications. However, whether TCM is effective in reducing the all cause or cardiovascular mortality in patients with CVD remains unknown and must be tested in large-scale RCTs with adverse cardiovascular events as primary end points.