The pharmacokinetics of oxazepam was studied in healthy volunteers. When oral doses of 15 mg were given to 8 subjects on 2 occasions 2.5 yr apart, the individual areas under the plasma concentration time curves did not differ significantly. Plasma clearance ranged between 0.050 and 0.171 l .times. kg-1 .times. h-1 and half-lives from 5.9-25 h. The urinary recovery of oxazepam conjugates was 67 .+-. 15 SD % of the dose given and the total recovery including fecal oxazepam was 70 .+-. 15 SD %. On multiple dosing (5 mg 3 times/day] stable steady-state concentrations were established. There was a tendency for slightly lower steady-state concentrations than predicted from single oral doses. During steady-state 86 .+-. 17 SD % of the dose was recovered in the urine over a 24 h period.