When KN3and NaN3powders or single crystals are irradiated with γ-rays, X-rays or ultraviolet light at liquid helium or nitrogen temperatures and subsequently heated many thermoluminescent glow peaks are observed between 47 and 255°K. The KN3glow curves have been analyzed by four different procedures. Thus four values of the activation energy have been obtained for each peak, and these occasionally differ by as much as 50 per cent. However, the agreement is usually much better. One of these analyses, a numerical kinetics treatment employing a large computer has been used to determine the activation energies and the preexponential factors listed below for the more intense glow peaks from both KN3and NaN3. The temperature of the glow peak maxima in °K, the activation energy in eV, and the preexponential factor in sec−1, obtained for the five most prominent KN3peaks are: 109, 0.28, 1.0 × 1011; 123, 0.29, 2.3 × 1010; 142, 0.32, 7.7 × 1010; 211, 0.63, 1.5 × 1013; 245, 0.84, 1.0 × 1015. The corresponding values for the nine most prominent NaN3peaks are: 47, 0.067, 1.4 × 105; 52, 0.046, 102to 105; 117, 0.23, 6.6 × 107; 133, 0.26, 3.5 × 107; 175, 0.38, 2.0 × 109; 189, 0.38, 2.0 × 108; 205, 0.39, 3.7 × 106; 233, 0.37, 1.5 × 106; 255, 0.47, 6.2 × 106. A few of these NaN3glow peaks might possibly be related to previously observed ESR and/or color centers.