Male Syrian hamsters were used to evaluate cadmium (Cd)-induced nephrotoxicity. Furthermore, they were treated with polyaspartic acid (PAA) in an attempt to prevent renal damage due to Cd. To induce renal proximal tubular damage, the hamsters were administered a single subcutaneous injection of cadmium chloride (CdCl2) at the dose of 3 mg/kg body weight. Within 24 hours, they exhibited significant proteinuria and an increased urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG). Renal histological changes consisted of degenerative changes in renal tubule cells, irregularly shaped nuclei with marginated chromatin and rounded mitochondria. The administration of PAA did not improve creatinine clearance or urinary protein excretion. The concentration of Cd in the renal tissue showed a gradual increase on day 3 following cadmium exposure. Cadmium nephrotoxicity appears to be more severe in Syrian hamsters than in rats or mice. Thus, this animal model appears to be excellent for studying Cd-induced nephrotoxicity.