Compelling epidemiological evidence suggests that the consumption of green tea is associated with beneficial effects in prevention of cardiovascular diseases. Plasminogen activator inhibitor-1 (PAI-1) is known to play a pivotal role in cardiovascular diseases including arteriosclerosis and hypertension. Increased PAI-1 was found in atherosclerotic lesions, and high PAI-1 plasma levels were associated with coronary heart disease. To determine the effect and molecular mechanism of green tea polyphenols (GTPs) on the regulation of PAI-1 expression in endothelial cells, bovine aortic endothelial cells were incubated with GTPs, and PAI-1 expressions were measured by western blot and enzyme-linked immunosorbent assay, respectively. GTPs significantly reduced PAI-1 expression and secretion in a time-dependent and dose-dependent manner. Inhibition of phosphatidylinositol 3-kinase (PI3K) with wortmannin markedly reversed GTPs repression of PAI-1 expression. In addition, the GTP-induced inhibitory effect was associated with an increased of activation of the protein kinase Akt. These results suggest that GTPs inhibit PAI-1 expression and its release from endothelial cells through the PI3K/Akt pathway, which may contribute to cardiovascular protection.