Angiogenesis is essential for reproduction, inflammation, development and wound repair. During these physiological processes, angiogenesis is tightly regulated. However, many pathological diseases, such as tumor growth and metastases, are driven by persistent deregulated angiogenesis. The integrin vitronectin receptor alphavbeta3 has been shown to mediate endothelial cell migration and proliferation and thus, plays a key role in angiogenesis. In the present study, the effect of alphav antisense phosphorothioate oligodeoxynucleotides (ODN) on alphavbeta3 expression, and on cellular migration and proliferation was assessed using human umbilical vein endothelial cells (HUVEC). We found that alphav antisense phosphorothioate ODN reduced alphavbeta3expression in some endothelial cell cultures and this resulted in a dose-dependent decrease in endothelial cell migration and proliferation. These results suggest that alpha v antisense phosphorothioate ODN could potentially be used as a novel class of angiogenesis inhibitors.