AbstractCampesterol, a plant sterol in nature, is known to have cholesterol lowering and anticarcinogenic effects. Since angiogenesis is essential for cancer, it was surmised that an antiangiogenic effect may be involved in the anticancer action of this compound. This study investigated the effect of campesterol on basic fibroblast growth factor (bFGF)‐induced angiogenesis in vitro in human umbilical vein endothelial cells (HUVECs) and an in vivo chorioallantoic membrane (CAM) model. Campesterol isolated from an ethylacetate fraction of Chrysanthemum coronarium L. showed a weak cytotoxicity in non‐proliferating HUVECs. Within the non‐cytotoxic concentration range, campesterol significantly inhibited the bFGF‐induced proliferation and tube formation of HUVECs in a concentration‐dependent manner, while it did not affect the motility of HUVECs. Furthermore, campesterol effectively disrupted the bFGF‐induced neovascularization in chick chorioallantoic membrane (CAM) in vivo. Taken together, these results support a potential antiangiogenic action of campesterol via an inhibition of endothelial cell proliferation and capillary differentiation. Copyright © 2007 John Wiley & Sons, Ltd.