Mechanical alloying (MA) has been used to synthesize Ti3SiC2 powder from the elemental Ti, Si, and C powders. The MA formation conditions of Ti3SiC2 were strongly affected by the ball size for the conditions used. MA using large balls (20.6 mm in diameter) enhanced the formation of Ti3SiC2, probably via an MA-triggered combustion reaction, but the Ti3SiC2 phase was not synthesized only by the MA process using small balls (12.7 mm in diameter). Fine powders containing 95.8 vol% Ti3SiC2 can be obtained by annealing the mechanically alloyed powder at relatively low temperatures.