Concentrations of the circulating endothelial cell products soluble E-selectin and von Willebrand factor are raised in hypertension, indicative of endothelial cell dysfunction. Our objective was to assess whether these high concentrations of cell products could be reduced with successful hypertension treatment and whether high concentrations were predictive of future adverse cardiovascular events. Blood samples were taken from 58 patients with hypertension (blood pressure: minimum 140/90; median 162/99 mmHg) to measure concentrations of von Willebrand factor, soluble E-selectin (by enzyme-linked immunosorbent assay), a smoking marker, and total cholesterol. A second sample was obtained from 15 patients when hypertension (median blood pressure 158/93 mmHg) was under control (median blood pressure 139/78 mmHg) 18 months (mean) later and blood tests repeated. All subjects were reassessed 36 months (mean) after the study began and cardiovascular endpoints such as myocardial infarction, stroke, or coronary artery bypass grafting were noted. There were significant reductions in systolic and diastolic blood pressure (both P = 0.001), von Willebrand factor level (P = 0.002) and soluble E-selectin level (P = 0.02) in the 15 patients followed up at 18 months. The change in systolic blood pressure correlated with the change in von Willebrand factor level (r = 0.57), P = 0.01). In the entire group of 58 patients, progression of atherosclerosis was evident in 11 patients who had raised von Willebrand factor level (P = 0.015) and slightly more vascular disease (P = 0.046) at outset than the other 47 patients in whom there was no clear progression of disease. High concentrations of von Willebrand factor in blood pressure, which mark endothelial cell damage, predict the appearance or progression of atherosclerosis in patients with hypertension. However, increased concentrations of von Willebrand factor in plasma can be reduced by successful treatment of hypertension.