1. Sodium-deficient diet failed to alter development and maintenance of severe renal hypertension produced in the rat by ligation of the aorta between the renal arteries.
2. High sodium diet did not alter the early phase of this hypertension, but significantly decreased blood pressure elevation in the late phases.
3. The decrease in blood pressure produced by high sodium intake does not appear to be mediated by renin suppression.
4. Frusemide effectively reduced blood pressure and renin at all phases.