IN a previous paper (Dingemanse, Huis in ‘t Veld and De Laat1), we reported that we had detected, by means of a chromatographic-colorimetric method, a new 17-ketosteroid in the urine of patients suffering from a dysfunction of the adrenal cortex. This 17-ketosteroid, to which we refer in this paper as 17-ketosteroid II, occurs in the urine of normal individuals, as a rule, in small quantities only, and may be completely absent. Considerable amounts, however, have been found in the urine of persons with ‘virilizing' tumours and with hyperplasias of the adrenal cortex.