The effects of angiotensin have been studied in four adult patients with the simple virilizing form of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. They were treated with hydrocortisone (25 mg/day) throughout this investigation. Plasma ACTH was normal in three cases, and androstenedione was normal in all cases. However, urinary pregnanetriol, plasma 17-hydroxyprogesterone (17 OHP), aldosterone, and renin activity was increased. The patients were then submitted to three protocols: sodium depletion (10 meq Na/day) for 5 days, sodium repletion (200 meq Na/day) for 5 days, and angiotensin infusion (sufficient to maintain a pressor response) for 60 min. Urinary pregnanetriol, plasma 17 OHP, and androstenedione levels increased in all patients after sodium depletion and decreased after sodium repletion. Plasma ACTH levels were not modified by changes in the sodium balance. Furthermore, angiotensin infusion increased aldosterone and 17 OHP plasma concentrations without any change in the plasma ACTH level. This study shows the direct action of angiotensin on adrenal steroidogenesis, at least in 21-hydroxylase deficiency. It confirms that even in the simple virilizing form, combined treatment with glucocorticoids and mineralocorticoids helps to normalize plasma 17 OHP levels.