The 99mtechnetium dimercapto-succinic acid scan provides an image of functional renal parenchyma. This static scan has specific indications and cannot be used simply in place of a 99mtechnetium diethylenetriaminepentaacetic acid scan. The major clinical indications for this investigation are the detection and/or evaluation of a renal scar, the small or absent kidney, an occult duplex system, certain renal masses, systemic hypertension or suspected vasculitis. The physiology of the 99mtechnetium dimercapto-succinic acid scan is reviewed briefly.