The tubular transport of urate was studied in 40 hypertensive patients and in 20 normal subjects by means of pyrazinamide and benzbromarone tests. There was a marked decrease in urate excretion per nephron in hyperuricemic patients with essential hypertension. Serum uric acid correlated inversely with fractional excretion of urate (r = -0.7450, p less than 0.001). Presecretory and postsecretory reabsorption of urate did not significantly differ between hypertensive patients with high uric acid levels and control subjects. Urate secretion was significantly reduced in hypertensive patients and in those with hyperuricemia showed a twofold decrease. Serum uric acid correlated inversely with tubular secretion of urate (r = -0.7091, p less than 0.001) in hypertensive patients. These findings indicate that impaired tubular secretion of urate is a potential mechanism of hyperuricemia in essential hypertension.