The absorption of ultrasonic waves in glycerin, castor oil, linseed oil, and olive oil was studied at various temperatures and at two frequencies, 3.157 and 3.95 megacycles per second, respectively. These liquids were chosen because of their high viscosity and correspondingly high absorption coefficients. As the viscosity of the liquids used depends to a considerable degree on the temperatures, the experiment permitted the calculation of the temperature coefficient of absorption to a good measure of precision and the results thus obtained agreed within the experimental error with the theoretical values for the coefficient. The sonic resonator interferometer developed by Hubbard, and adapted by Fox for use with liquids in this laboratory, was used.