Rho-kinase (ROCK) is one of the effectors of the small GTP-binding protein Rho. Accumulating evidence suggests that the Rho/ROCK system may play an important role in the pathogenesis of atherosclerosis and coronary vasospasm via its action in vascular smooth muscle cell contraction, endothelial function and the inflammatory process. Recent observations suggest that the beneficial cardiovascular effects of statins may, at least in part, derive from the inhibition of ROCKs. Fasudil is a ROCKs inhibitor which has potential benefits in coronary artery spasm and myocardial ischemia. In this review, we aim to describe the current understanding of ROCKs signaling and their roles in the pathophysiology of atherosclerosis and coronary spasm.