A novel and facile approach is demonstrated to dramatically enhance thermoelectric properties by means of introducing one-dimensional (1-D) silver nanowires (AgNWs) into a three-dimensional (3-D) Bi 2 Te 3 matrix in order to construct 1-D/3-D structured nanocomposites. The influence of different concentrations of AgNWs on the morphology and thermoelectric properties of Bi 2 Te 3 is investigated in detail. The results show that the dispersed AgNWs effectively suppress grain growth and form new interfaces with the Bi 2 Te 3 matrix. In contrast to pure bulk Bi 2 Te 3 , almost all bulk samples dispersed with AgNWs exhibit the much lower thermal conductivity and higher power factors. Consequently, the maximum ZT of the AgNW-dispersed Bi 2 Te 3 nanocomposites is amazingly found to be 343% higher than that of the pure Bi 2 Te 3 . These results demonstrated that the dispersion of AgNWs could form new interfaces with the matrix and introduce defects to cause strong scattering of long-wavelength phonons, and therefore significantly reduce the lattice thermal conductivity. Our study confirms that introducing 1-D nanodispersoids into a 3-D thermoelectric matrix is promising approach to improving ZT values significantly.