Differential scanning calorimetry has been used to determine kinetic parameters for the thermal decomposition of N,2,4,6-tetranitro-N-methylaniline (tetryl) in the decay phases. The mean value of the thermal decomposition enthalpy is Delta H-D = -404 kJ mol(-1), The influences of several factors on the kinetic parameters and compensation effects are presented. The kinetic parameters are used to predict critical temperature and mole fraction of the thermal decomposition products during the induction phase.