PbSe nanowires (NWs) have been synthesized by using a single-source precursor route. Carefully controlling the conditions of individual reactions leads to PbSe NINs with well-defined diameters (8-25 nm) and lengths (100 nm-1 mu m). The as-grown PbSe NWs are highly crystalline, defect free, and readily dispersible in organic solvents. The NWs have been characterized by X-ray diffraction and high-resolution transmission electron microscopy.