Microalbuminuria is a marker of the endothelial dysfunction, which appears in 30-40% of clinically manifest diabetic patients, but it could be present in early stages of diabetes characterised by hyperinsulinism/insulin resistance. Angiotensin II plays an important role in the endothelial dysfunction progression, so drugs influencing its secretion and action on angiotensin receptors are intensely studied. We proposed to follow the ramipril effect upon microlabuminuria in two patients group: one having type 2 diabetes mellitus and the other having metabolic syndrome without clinically manifest diabetes. Our results evidenced that this angiotensin-converting- inhibitor reduces significantly the microalbuminuria, the renoprotective effect beeing dose-dependent and influenced by the severity of the metabolic disturbances.