Streptozotocin (STZ)-diabetes was induced in spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats with their litter mates serving as controls. The animals were studied for 6 months and blood pressure, weight, urinary and serum glucose, creatinine clearance, total proteinuria and albuminuria were measured monthly. With induction of diabetes, there was a significant rise in creatinine clearance in the hypertensive diabetic animals (SHR-STZ). SHR-STZ (n = 6) developed higher levels of total proteinuria than WKY-STZ (n = 5) although the rise from basal levels was only apparent after 20 weeks of diabetes. All SHR-STZ developed albustix positive proteinuria after 6 months of diabetes. In the first 12 weeks after onset of diabetes, albuminuria increased to a greater degree in SHR-STZ than in WKY-STZ. This occurred before there was a detectable rise in total proteinuria. The SHR-STZ model of genetic hypertension and diabetes may be suitable for the evaluation of antihypertensive therapy in human diabetic renal disease.