The episodic secretion of aldosterone depends on the dietary sodium intake, alterations in posture and follows ACTH circadian rhythm. Aldosterone daily profiles have been studied in 23 supine essential hypertensive patients on normal sodium intake. Secretory pulses at a frequency of two to five pulses per 12 hr have occurred, independent of PRA levels. Among 13 patients with normal PRA two lost pulsatility when sodium was loaded (10 g/24 hr) and the same happened with two others on sodium restricted diet (2 g/24 hr). These results suggest a profound effect of dietary sodium intake on the pulsatile pattern of aldosterone secretion, particularly in normal PRA essential hypertension.