Bladder dysfunction in the elderly is an enormous public health problem. Laboratory research using animal models has to date not yielded clinically useful new information. Demographic and urodynamic studies in selected elderly patients indicate that neurological disease and bladder outlet obstruction are the primary causes for voiding dysfunction. The effect of aging per se on the urinary bladder is not known. Elderly patients who have bladder dysfunction should be evaluated with a careful history and physical examination combined with a practical urodynamic evaluation rather than simply being labeled as having "bladder dysfunction in the elderly."