Renal dipeptidase (DPEP1) or dehydropeptidase-I (E.C.3.4.13.11) is a kidney membrane enzyme which hydrolyzes a variety of dipeptides. DPEP1 is implicated in the renal metabolism of glutathione and its conjugates and is also responsible for hydrolysis of beta-lactam antibiotics. Using a human DPEP1 cDNA probe, we mapped the human renal dipeptidase gene to human chromosome 16 at band q24 by in situ hybridization.