Seven healthy women chronically (greater than 6 months) treated with oral contraceptives and 7 age- and weight-matched female controls were studied. Each subject was given 20 mg fluocortolone orally and the plasma concentrations of total and unbound fluocortolone in multiple samples obtained during the following 24 h were determined by HPLC and equilibrium dialysis. In the subjects on oral contraceptives there was no significant change in total clearance, unbound clearance or volume of distribution at steady-state of total and unbound fluocortolone, but there was a significant increase in hydrocortisone concentration compared to the control subjects. It appears that the elimination of the synthetic corticoid fluocortolone was not impaired by chronic administration of contraceptive steroids.