This paper addresses the problem of low-power fanout optimization. We show that due to neglecting short-circuit current, previous analytical techniques proposed to optimize the area of a fanout tree may result in excessive power consumption. This shows, to achieve a low-power fanout tree, an accurate power consumption model should be used as the objective function. Moreover, we propose an efficient method to minimize the total power consumption of a fanout tree by using MTCMOS and Multi-Vt techniques. Experimental results show that depending on the activity factor of the circuit, the proposed technique can reduce the power consumption of the fanout tree 18% to 45%. Categories and Subject Descriptors B.6.3 [Design Aids]: Automatic synthesis, Optimization General Terms Algorithms, Design, Performance Keywords Low-power design, fanout optimization, fanout tree, buffer chain