Copper indium diselenide (CuInSe 2 ) powders were successfully synthesized using the microwave-assisted solvothermal process at 2001C within a short time. The reaction time for preparing singlephased CuInSe 2 was significantly shortened with the developed microwave treatment. The microwave field enhanced the mobility of the reactants, thereby resulting in an accelerated reaction rate. CuSe was the major intermediate product during these reactions and the CuInSe 2 phase was gradually formed as the reaction temperature and time were increased. The prepared powders exhibited plate-like and spherical shapes, and the fraction of plate was increased with increasing reaction time. The solvothermal route combined with the microwave heating system was found to significantly promote the formation of plate-like particles.