Nanostructuring may contribute to distinct enhancement in thermoelectric (TE) performance via increasing the phonon scattering and density of states. In the present study, AgPb18SbTe20 (LAST-18) powders with a heterostructure of nanorods and nanocubes are synthesized by a facile one-pot solvothermal method using cheap chemical reagent as starting materials and cetyltrimethyl ammonium bromide (CTAB) as a surfactant. The results show that CTAB is crucial for the formation of nanorods owing to the preferential growth on the {1 0 0} faces or along the [1 0 0] direction with high surface energy. However, the powders are characterized by nanoparticles in case no surfactant or mass equivalent SDBS are used under the same condition. In addition, a relatively high Seebeck coefficient of the hot-pressed bulk LAST-18 with 5 vol.% heterogeneous nanopowders was obtained at high temperature range. (C) 2012 Elsevier B.V. All rights reserved.