Adrenomedullin (ADM), a novel peptide recently isolated from pheochromocytoma, eliciting vasorelaxing activity, is the strongest among all known peptides. ADM mRNA has been detected in the adrenal medulla, cardiac tissue, lung, and kidney. İmmunohistochemical studies have demonstrated the localization of ADM in glomeruli, tubules, and collecting cells of the kidney. ADM has diuretic and natriuretic actions, which are mediated by increases in glomerular filtration rate and a decrease in distal tubular sodium reabsorption. Clinically, plasma ADM and urinary levels are altered in patients with different renal disease. Further investigations are required to address the importance of ADM under various conditions.