We hypothesized that in essential hypertensive patients (EHs), plasma levels of pro-atherogenic adhesion molecules would be increased and related with urine albumin excretion (UAE). Thus, this study was aimed at evaluating biochemical markers of endothelial activation and their relationship with UAE in a group of patients with uncomplicated EH. In basal condition soluble forms of adhesion molecules intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1, as well as 24-h UAE were assayed. One hundred patients with essential hypertension and no diabetes or ultrasonographic evidence of atherosclerosis were included in the study. Seventy normotensive healthy subjects served as controls. EHs were first studied overall, than were divided into two subgroups: those with UAE ≥20 mcg/min MAUs and those with UAE <20 mcg/min (non-MAUs). ICAM-1 (P < 0.001) and VCAM-1 (P < 0.0001) plasma concentrations were higher in EHs than in controls. Microalbuminuric EHs had greater levels of adhesion molecules than non-MAUs (ICAM-1 P = 0.04; VCAM-1 P = 0.02, respectively). In EHs UAE was correlated with ICAM-1 (r = 0.29, P = 0.003), and VCAM-1 (r = 0.30, P = 0.002). These associations were confirmed in multiple regression models (P = 0.02 for both ICAM-1 and VCAM-1) including, along with adhesion molecules, age, body mass index and blood pressures. Our findings show that in essential hypertension there is a very early activation of endothelial adhesion molecules favouring atherosclerosis.