Heavy reversible proteinuria induced by antihypertensive treatment with low doses of captopril has recently been reported by our group in psoriatic patients. To ascertain whether an increased permeability of the glomerular basal membrane of psoriatics can lead to an enhanced urinary excretion of albumin independently from the presence or absence of coexisting diabetes or hypertension, the latter parameter was measured in 39 patients affected by diffuse psoriasis. A high prevalence of microalbuminuria was observed in diabetic and hypertensive psoriatics. Moreover, a direct correlation was found between the diastolic blood pressure (BP) values and the urinary excretion of albumin in the entire group of psoriatics, thus suggesting systemic hypertension as one of the factors responsible for proteinuria in these patients. However, more than 50% of normotensive psoriatics showed an enhanced excretion of albumin. Since microalbuminuria has been indicated as a reliable index to predict the development of renal impairment, the finding of an enhanced albumin loss in psoriatics represents a further risk factor in these patients, who are particularly susceptible to experience cardiovascular complications.