Diabetic nephropathy is one of the major long term complications responsible for mortality in diabetes mellitus. While strict metabolic control of diabetes probably has a positive influence on kidney disease, most evidence supports the view that the process leading to end-stage renal failure has become independent of the metabolic disturbances of diabetes, and that haemodynamic factors in established nephropathy have become the predominant causes of progression of renal damage. In particular, increased intraglomerular pressure is thought to play a crucial part in the development of diabetic nephropathy. Therefore, drugs that can reduce intraglomerular pressure are of interest in treatment of hypertension in diabetic patients. The angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce intraglomerular pressure in animal studies, and the use of these drugs to treat insulin-dependent diabetics with hypertension has produced a reduction in the rate of decline of glomerular filtration rate. Although some beta-blockers can also have beneficial effects on renal function, they may produce unwanted metabolic effects. Thus the ACE inhibitors seem to be the most suitable antihypertensive drugs for diabetic patients.