Rosmarinic acid frequently found as a secondary metabolite in herbs and medicinal plants, has exhibited antimicrobial, antiviral, antioxidative, and anti-inflammatory activities. The proliferation and migration of human aortic smooth muscle cells (HASMC) in response to activation by various stimuli plays a critical role in the initiation and development of atherosclerosis. This study was conducted to examine the effects of Rosmarinic acid on the proliferation and migration of HASMC. Rosmarinic acid suppressed the proliferation of HASMC via induction of the expression of apoptotic proteins including cleaved poly ADP-ribose polymerase (PARP), and caspase-3. Rosmarinic acid decreased anti-apoptotic Bcl-2 and increased pro-apoptotic Bax. Moreover, treatment of rosmarinic acid decreased the G1/S cycle regulation proteins (cyclin D1, cyclin E, CDK2, CDK4 and CDK6) and increased p21, p27 and p53. Rosmarinic acid also blocked HASMC migration via suppression of MMP-9 and MMP-2. Taken together, these results indicate that rosmarinic acid has the potential for use as an anti-atherosclerosis agent.