Although a number of excellent paper chromatographic technics are available for resolution of steroid mixtures (l-3), the separation of nouketonic hydroxy steroids has not been satisfactorily investigated. The difficulty in determining the chromatographic behavior of the free nonketonic st)eroids has been the lack of a suitable color reaction for locating the compounds on a chromatogram. Estrogens have been chromatographed on paper, but their detection required coupling with a dye (3). Antimony trichloride appeared to have the necessary characteristicas for reacting with steroids to give colored products. Earlier investigators had utilized solutions of this reagent in glacial acetic acid or chloroform for estimation of urinary steroid metabolites (5) and for spectrophotomet,ric comparison of steroidSbC4 product,s (6). More recently atItimony trichloride (20 % in chloroform) (7, 8), antimony pentachloride (8, IO), and antimony trichloride in an atmosphere of chlorine (I I ) have been used for the detection of steroids on paper chromatograms. The use of another antimony trichloride preparation whose application has proven to be very simple, versatile, and effective in the detection of steroids is to be discussed here. Characteristic colors were observed on paper when various steroids were treat’ed lvith antimon! trichloride in nitrobenzene (13), hydroxylated compounds being partic+ularly reactive. This proredure will permit. the examination of non-