Salivary aldosterone measurements can be used to study aldosterone secretion and metabolism noninvasively. Salvia and plasma aldosterone concentration were highly correlated during all periods of study; during adrenocorticotrophic hormone (ACTH) administration, a relatively greater amount of aldosterone appeared in saliva; during dexamethasone administration, a relatively smaller amount of aldosterone appeared in saliva. As plasma cortisol increased with ACTH administration there was an increased relative amount of aldosterone in saliva. DOC (11-deoxycorticosterone) was found in saliva only during ACTH administration. Corticosterone was identified during baseline periods. Salivary aldosterone concentrations were independent of flow. The data indicate that saliva is an accessible bodily fluid which may be used to monitor the changes in nonprotein bound plasma steroid hormone concentration in children.