21-Acetoxypregneno-lone was give in 7 ambulatory patients with demonstrably active rheumatoid arthritis of moderate or marked degree. The age of the patients studied ranged from 19 to 65 yrs. The duration of the rheumatoid arthritis ranged from 2.5 to 38 yrs., with the following joints chiefly involved: shoulders, wrists, elbows, knees, metacarpophalangeal and interphalangeal joints. Cholesterol, 100 mg. intramusc. injd. daily for 3 days prior to the admn. of 21-acetoxypregnenolone, resulted in no improvement and in 3 patients and aggravation of symptoms. 21-Acetoxypregnenolone was then admd. intramusc., 100 mg. on the 1st day, 200 mg. on the 2d day, and 300 mg. daily thereafter for a total of 14 days, after which the dosage was decreased to 200 mg. and the interval lengthened to 2 days. In 3-5 days in each of the 7 patients a reduction in the swelling, lessening of the pain, and increased motion in the joints was seen. At the end of 2 weeks, improvement was rated in 2 patients as marked, and in 5 patients as very marked.