A rapidly growing body of data support the concept of endothelin as a paracrine acting endothelial regulators. The system of endothelin peptides--their chemical structure, physiological activity and role in cardiovascular pathological processes are reviewed. Molecular specificity, isoforms, and physicochemical parameters of the endothelin-converting enzyme (ECE) characterize this novel metalloproteinase as important regulator, that catalyses final step in the biosynthesis of endothelins. The role of the general endothelial system for various cardiovascular pathological states, including congestive heart failure and myocardial infarction, arterial hypertension, atherosclerotic vascular diseases is discussed. Therapeutic approaches with some endothelin receptor antagonists and ECE inhibitors are discussed, and endothelin system therefore represents a likely target for the development for the novel pharmaceutical agents.