Microalbuminuria, originally described more than 3 decades ago as a predictor of nephropathy in patients who had type 1 diabetes mellitus and associated with higher cardiovascular risk, is now linked with increased risk for cardiovascular events rather than progression to end-stage kidney disease. This article reviews the role of microalbuminuria in the context of atherosclerotic vascular disease. It presents the methods for microalbuminuria assessment in clinical practice, its relations with other cardiovascular risk factors, and the pathophysiologic associations between microalbuminuria and vascular damage. In addition, this article discusses the prognostic significance of microalbuminuria for cardiovascular disease as well as existing therapeutic interventions for reducing urine albumin excretion in patients who are at high cardiovascular risk.