Temperature dependence of ultrasonic attenuation and ultrasonic Gruneisen parameter are investigated in alkali halides in the range 80–300 K. The calculations use a computer program, developed by the authors, for implementing Nava’s modified formulation of Woodruff’s theory. These calculations are done for NaCl, NaF, and LiF for longitudinal and shear waves along the [100], [110], and [111] directions. Compared to calculations based on original Mason formulation, it was found that in most cases the results are in better agreement with the experimental data. The results also help to throw some light on relative merits of different theories of attenuation.