1. Six patients with active rheumatoid arthritis showed prompt, but transient, improvement after the administration of nitrogen mustard.
2. Nitrogen mustard produces depletion of the cholesterol esters and ascorbic acid of the adrenal cortex in the experimental animal.
3. ACTH produces depletion of the cholesterol esters and ascorbic acid of the adrenal cortex.
4. Further investigation to determine the efficacy of nitrogen mustard in the treatment of rheumatoid arthritis is indicated.