Mechanical alloying behavior of the PbTe intermetallic compound, which is used for thermoelectric generation, has been investigated with milling time and ball-to-powder weight ratio. Formation of PbTe alloy was completed by mechanical alloying of the as-mixed Pb and Te powders for 2 minutes at ball-to-powder weight ratio of 2 : 1. In situ measurement of the abrupt temperature rise during the ball milling process indicated that the PbTe intermetallic compound was formed by a self-sustained reaction rather than diffusional reactions. Lattice constant of PbTe alloy fabricated by mechanical alloying, 0. 6462nm, was not varied with milling time and ball-to-powder weight ratio. This value of the lattice parameter is in excellent agreement with 0.6459nm, which was reported for PbTe powders processed by melting and grinding.