Microalbuminuria has been proposed as a potential atherosclerotic risk factor in hypertensive individuals. The aim of this cross-sectional population study was to analyse whether microalbuminuria is related to a higher prevalence of cardiovascular disease, and a more atherogenic risk profile, and reversely related to the use of antihypertensive drugs. In a major health screening at the State University Hospital in Copenhagen, including excretion, glomerular filtration rate, (BP), electrocardiogram, body mass index, plasma lipoproteins, fibrinogen, and albumin, and information regarding a history of acute myocardial infarction, smoking, and antihypertensive drugs, 1254 participants without diabetes mellitus or renal/urinary tract disease had arterial hypertension. Age range was 30-70 years. Microalbuminuria (nocturnal urinary albumin excretion > 15 μg/min) occurred in 5%, and cardiovascular disease (previous acute myocardial infarction or electrocardiographic Q-waves) also in 5% of the study population. Microalbuminuric hypertensive subjects were characterized by higher age and systolic BP, and a male predominance, as compared to normoalbuminuric hypertensive subjects. The frequency of cardiovascular disease was similar in the two groups. In contrast, when analysed as a continuous variable, a one unit increase in the logarithmically transformed urinary albumin excretion significantly increased the likelihood of cardiovascular disease (odds ratio [95% confidence interval] 1.32 (1.02-1.70); P < 0.05), and this relation was independent of age, sex, and conventional atherosclerotic risk factors. Participants who were effectively treated with antihypertensive drugs did not have a lower urinary albumin excretion than insufficiently treated or untreated participants. It is concluded that slightly elevated albumin excretion in the urine is not only a pressure-dependent functional phenomenon in the glomerular vessel walls, but associated with permanent atherosclerotic abnormalities in the entire vascular system.