A twenty per cent solution of formaldehyde was used in the treatment of a case of alopecia areata in a young girl, where there was a bare spot three inches in diameter on the scalp. The remedy was applied every day until the skin became slightly inflamed, then a sedative ointment was applied, until the inflammation subsided, when the formaldehyde was again resorted to. The treatment was persisted in for more than six months. The results were very satisfactory. There was a heavy growth of hair in every way similar to the rest of the hair.