Microalbuminuria continues to receive attention in patients with hypertension, even if they do not have diabetes mellitus. The attention appears deserved, because microalbuminuria has emerged as an important risk factor for left ventricular hypertrophy, myocardial infarction, stroke, peripheral vascular disease and retinopathy, independent of blood pressure. Microalbuminuria may be a useful measurement during pregnancy and appears particularly indicated in following up women who develop pre-eclampsia during pregnancy, In addition to diabetes, increased blood pressure and age, the smoking habit appears to be the most important factor contributing to microalbuminuria, although other influences including uranium exposure have been implicated. We need to learn more about the mechanisms of microalbuminuria, particularly in non-diabetic hypertensive patients. Microalbuminuria is potentially reversible. All antihypertensive agents appear to reduce microalbuminuria. In diabetic patients, angiotensin-converting enzyme inhibitor therapy is effective in reducing renal disease progression, even in the absence of hypertension. Antioxidant therapy may be effective. Stopping smoking should be the initial antioxidant measure.