Understanding the nature and role of endothelium-derived hyperpolarizing factor appears to be crucial in the quest for improved treatments for hypertension, diabetes, ischemia-reperfusion and other vascular disorders.EDHF 2002 contains the proceedings of the Fourth International Symposium on endothelium-dependent hyperpolarizations and will be of interest not only to physiologists and pharmacologists puzzled by the complexity of the interactions between the endothelium and underlying vascular smooth muscle cells, but also clinical researchers and physicians treating patients with cardiovascular diseases.