Polycrystalline Ni0.05Mo3Sb5.4Te1.6 thermoelectric (TE) material samples were mixed with NiSb nanoparticles (60-80 nm) in 0, 0.034, 0.074 and 0.16 vol fractions, then hot-pressed and their TE transport properties were characterized. There was a gradual increase in electrical conductivity with the addition of NiSb nanoparticles. The electrical conductivity (sigma) of the 0.16 sample was increased by 163% compared to the NiSb-free sample. Except for the 0.16 sample, all samples showed alloy scattering (sigma similar to T-0.5). With an increase in NiSb content, the Fermi energy appeared to be reduced, getting closer to the valence band edge. For all samples, the variation in lattice thermal conductivity with temperature (kappa(l) similar to T-0.27) was very similar, indicating that the mode of phonon scattering was the same in all samples.