Thirty-two yeast species (162 strains) have been examined for their ability to utilize ethylamine hydrochloride as sole source of nitrogen. The possible taxonomic use of this property is discussed. The utilization of ethylamine was, with one exception, found to coincide with an ability to utilize L(+)-lysine. In view of the fact that non-industrial yeasts readily utilize ethylamine, its use as a cheap, selective nitrogen source in media employed for the determination of purity of pitching yeast should be considered.