There is convincing epidemiological evidence indicating that the serum levels of high density lipoprotein (HDL) cholesterol are inversely related to the risk of vascular events. Similarly, intervention trials, involving healthy populations and patients with coronary heart disease (CHD), have shown that raising the serum levels of HDL is associated with a significant decrease in the risk of vascular events. It follows that serum HDL levels must be considered when assessing risk and setting therapeutic goals. Some of the currently available national treatment guidelines reflect this view. The present review considers the place of serum HDL measurement in the prevention of vascular events.