SummaryThirty cases with proteinuria either asymptomatic or associated with hypertension were selected through rigid Criteria. 17 patients are normotensive and 13 have a blood Pressure at one or multiple control over 140-90 mmHg. Renal biopsies on such patients emphasize the frequency of vascular lesions. Arteriolar lesions were the only abnormality in twenty one cases. Glomerular lesions were observed in only 8 patients. In 14 patients, with a mean age of 21, vascular lesions are noticed in the absence of hypertension. Our own observation and data of the litterature are in favour of a primary arteriolar disease.