The thermoelectric properties of the CoSb3 nanoparticle films, which have been prepared via the Low Pressure Chemical Vapor Deposition, were measured in the temperature range from 300 to 800 K. The resistivity of the CoSb3nanoparticle films is one order of magnitude lower than the single crystal CoSb3bulk sample. The measured values of the thermal conductivity of the CoSb3 nanoparticle films are in the range from 1.08 to 4.05 Wm－1K－1, which are much lower than that of the single crystal CoSb3 samples. This suggests that the nanostructure results in a significant reduction of the thermal conductivity. The highest thermoeletric optimal value was 0.114 and obtained at 773 K. The discussed nanoparticle films are promising for realizing new types of highly efficient thermoelectric semiconductors.