Single-crystalline arrays of PbS, PbSe, and PbTe nanowires (Figure: PbS) with diameters ranging from 40-200 nm and lengths up to 100 pm have been synthesized by a chemical vapor transport approach. Electrical and thermal characterization was performed to investigate their potential as thermoelectric materials. Compared to bulk, the nanowires exhibit reduced thermal conductivity below 100 K by up to 3 orders of magnitude, suggesting that they may be promising thermoelectric materials.