Microalbuminuria (MA), a microvascular irregularity of the blood-urine interface within kidney glomeruli, may reflect the renal sign of global endothelial dysfunction, and has been associated with an elevated risk of serious cardiovascular events including stroke. This relationship appears graded, with higher levels of MA being independently associated with a greater magnitude of vascular risk over time. Furthermore, the presence of MA appears to independently predict poorer clinical outcomes following acute stroke. Screening for MA is relatively easy and inexpensive and could be effective in identifying stroke patients at risk for unfavorable outcomes. Reduction of subclinical albuminuria in stroke patients could be a clinically relevant endpoint worthy of pursuit by pharmacological treatment since the antiproteinuric effects of several established therapies appear to parallel better cardiovascular prognosis including better stroke outcomes, among subjects at high vascular risk. This review depicts the compelling epidemiological and clinical evidence relating MA to stroke, and presents the rationale for conducting future studies to assess the role of MA as a potential therapeutic target in persons with, or at risk for stroke.