Results of thermal analysis performed at different heating rates on the composition Bi5Ge20Se75 are reported and discussed. The values of crystallization temperature (T-c) and the peak temperature of the crystallization (T-p) were found to be dependent on the heating rates. The activation energy of crystallization E(c) was evaluated by five different methods. The average value of E(c) is equal to 119.64 +/- 6.97 kJ mol(-1). The crystallization data are examined in terms of recent analysis developed for nonisothermal conditions. The results indicate a two-dimensional crystal growth for the investigated composition.