Polyaniline (PANI)-coated multi-walled carbon nanotubes (PANI-CNTs) were firstly synthesized by in situ polymerization and then incorporated into the PANI matrix by hot pressing to fabricate bulk PANI-CNT/PANI composites. The composites showed homogeneously dispersed CNTs into the PANI matrix with a strong interface interaction. Thermoelectric measurements at room temperature showed a significant enhancement in both the electrical conductivity and Seebeck coefficient with the addition of PANI-CNTs. At the same time, relatively low thermal conductivity was also obtained. The maximum electrical conductivity and Seebeck coefficient of the composites were up to 2.8 x 10(3) S/m and 21.6 mu/K, respectively, and the maximum figure of merit reached 1.0 x 10(-3) more than three orders of magnitude higher than that of neat PANI. This study proposed a novel and effective way to fabricate bulk PANI/CNT composites with enhanced thermoelectric properties.