Parathyroid hormone has been recognized as an important factor in the regulation of renal function since the 1920s. Early investigations mainly characterized the role of the hormone in calcium and phosphorus metabolism. Subsequently, significant contributions have been made to the understanding of the influence of parathyroid hormone on acid-base balance and amino acid excretion. The following is a review of the effects of parathyroid hormone in the regulation of renal function with special emphasis on new developments.