Summary Hippuric acid was identified as a constituent of the nonprotein nitrogen fraction of milk. A method of measuring the hippuric acid content of milk was developed. This method is based on continuous ether extraction of tryptic digested, acidified skimmilk and measurement of extracted nitrogen by the Kjeldahl procedure. The amounts of hippuric acid in 14 samples of skimmilk, gathered during the period July to January, were determined. These values ranged from 3.1 to 6.4mg./100ml. of skimmilk and averaged 5.1mg./100ml.