Differential scanning calorimeter (DSC), under non-isothermal condition, was used to study the glass transition kinetics and the crystallization mechanism of Se 90 Cd 8 Bi 2 and Se 90 Cd 6 Bi 4 glassy alloys. Two approaches, namely Moynihan and Kissinger, were used to calculate the relaxation activation energy (E t ) from the dependence of the glass transition temperature (T g ) on the heating rate (β). Results reveal that E t decreases with an increase in Bi content which indicates that thermal stability is improved. This is attributed to the formation of Se–Bi bonds which are stronger than Se–Cd bonds and heavily cross-link the structure. In addition, the kinetic analysis of the crystallization peaks was performed using Ozawa, Kissinger, Takhor and Augis–Bennett relations. The values of the crystallization activation energy (E c ) and Avrami exponent (n) of the two alloys were evaluated. The obtained values of E c , calculated from the above mentioned relations, were found to be in good agreement while the average calculated values of Avrami exponent (n) are (2.3±0.1) for Se 90 Cd 8 Bi 2 and (1.7±0.1) for Se 90 Cd 6 Bi 4 which indicating that the crystal growth in the two alloys occurs in one dimension.