Excessive proliferation of vascular smooth muscle cells is a crucial event in the pathogenesis of several cardiovascular diseases, including atherosclerosis and restenosis. In this study, we reported that stigmasterol was effective in inhibiting vascular cell proliferation exemplified by using A7r5 cells stimulated by Ang II. Mechanism analysis showed that this inhibiting effect mainly occurred by the arrest of the cell-cycle and promotion of apoptosis. In addition, stigmasterol inhibition effects were detected in association with decreased ROS production, enhanced SOD and CAT activity, decreased abundance of cyclin A, CDK2, PCNA, bax and bcl-2, and increased levels of p53 protein. Our study provided implications for the development of therapeutic strategies to protect against certain cardiovascular pathologies, such as atherosclerosis and restenosis.