Diabetes is associated with both premature cardiovascular disease and renal disease. The presence of microalbuminuria is itself an independent risk factor for the development of cardiovascular disease. Angiotensin-converting enzyme (ACE) inhibitors were initially shown to slow the progression of established renal disease in patients with type 1 diabetes. Subsequent trials have demonstrated a similar benefit in patients with type 2 diabetes and with the use of angiotensin II receptor blockers (ARBs). The use of ACE inhibitors to prevent cardiovascular events in patients with established cardiovascular disease but not left ventricular dysfunction was established in two large randomised trials – HOPE and EUROPA. These benefits were maintained within the diabetic subgroups of these trials and appear to be independent of blood pressure lowering. The LIFE trial also provides evidence of the benefits of ARBs in reducing cardiovascular events in a high-risk population of diabetic patients with hypertension and left ventricular hypertrophy. Ideally, therefore, all diabetic patients with renal or cardiovascular disease should be treated with ACE inhibitors or ARBs.