In this paper, we report the direct synthesis of Li7La3Zr2O12 with the cubic garnet-type structure at low temperature with a lattice constant of 13.0035 angstrom. The synthesis condition is optimized to be at 750 degrees C for 8 h with 30 wt% excess lithium salt. No intermediate grinding was involved in this straightforward route. Without the adventitious of Al3+, the cubic Li7La3Zr2O12 is unstable above 800 degrees C and has an ionic conductivity of the order of 10(-6) S cm(-1). (C) 2012 Elsevier Ltd. All rights reserved.