Urotensins were originally discovered from urophysis, a fish neuroendocrine organ located in the caudal spinal cord. Human homologs of urotensins have recently been identified. Urocortins (urocortin 1, 2, and 3) are human homologs of urotensin I and belong to the corticotropin-releasing hormone (CRH) family peptides. Urocortins have cardiovascular effects, such as vasodilatation and positive inotropic action, which are mediated by CRH type 2 receptors. Human urotensin II is a cyclic peptide consisting of 11 amino acids. Human urotensin II acts on the G-protein-coupled receptor GPR14 and exerts potent vasoconstrictor effects. In certain blood vessels, it also causes vasodilatation, possibly via the release of vasodilator substances, such as NO, from the vascular endothelium. Plasma concentrations of urotensin II are elevated in patients with chronic renal failure, heart failure, or diabetes mellitus. The expression of urotensin II is enhanced in cardiac tissue obtained from patients with heart failure or in blood vessels with atherosclerotic lesions. It can be concluded that human homologs of urotensins (urocortins and urotensin II) are novel cardiovascular peptides that may be related to the pathophysiology of cardiovascular disease.