In about 15% of cases hypertension is caused by renal diseases, including unilateral and bilateral parenchymatous nephropathies, renal artery stenosis and renin producing tumors. Important pathogenic determinants are the sodium volume status and the renin angiotensin system. The level of the blood pressure may also depend on the duration of hypertension. An increase in peripheral resistance plays a more important role than an increase in cardiac index. Simultaneous determination of the renin activity in both renal veins is of decisive importance in the diagnosis of renal artery stenosis. Drug treatment of renal hypertension is not essentially different from that of essential hypertension. Surgical procedures include revascularization, uninephrectomy and, in uncontrollable hemodialysis patients, binephrectomy.