Microalbuminuria is common among general population, particularly in patients with diabetes mellitus or arterial hypertension. Microalbuminuria (MA), conventionally defined as a urinary albumin excretion (UAE) of 30–300 mg/day, is recognised as a marker of endothelial dysfunction. Furthermore, it represents an established risk factor for cardiovascular morbidity and for end-stage renal disease in individuals with an adverse cardiovascular risk profile. There is growing evidence from prospective observational trials that UAE levels well below the current MA threshold (“lowgrade MA”) are also associated with an increased risk of incident cardiovascular disease and all-cause mortality. Such association has even been shown in apparently healthy individuals (without diabetes or hypertension). As assays for albuminuria screening, reliable even for the lower ranges, are commercially available, disease screening may play an important clinical role in MA, comparable to the role of blood pressure and lipid screening. Because of its low cost and wide availability, measurement of albuminuria is an attractive and cost-effective screening test that is especially suitable as the first step in the large-scale diagnostic work-up of hypertensive patients.