Caffeic acid phenethyl ester (CAPE) is a component of honeybee hives with various beneficial properties. Tissue factor (TF), the key trigger of thrombosis, is expressed in human endothelial cells. This study was designed to investigate whether CAPE modulates TF expression in human aortic endothelial cells (HAECs). Western blots and real-time polymerase chain reactions were performed. CAPE (10(-7)-10(-5) M) inhibited tumor necrosis factor (TNF)-α induced endothelial TF protein expression by 2.1-fold at 10(-5) M (p<0.0001). Similarly, TF surface activity was reduced (p<0.02). In contrast, TF mRNA expression, TF promoter activity, and mitogen-activated protein (MAP) kinase activation remained unaltered. In conclusion, CAPE inhibits TF protein expression and activity at the posttranscriptional level thereby exhibiting anti-thrombotic potential.