Lead sulfide (PbS) nanorods with a high aspect ratio were prepared by a novel thioglycolic acid assisted hydrothermalmethod. X-ray diffraction and transmission electron microscopy revealed that the product was rod-like PbS with cubicrock-salt structure. Further characterizations by selected area electron diffraction and high-resolution transmissionelectron microscopy showed that the PbS nanorods were single crystalline in nature. Furthermore, the mechanismand critical factors for the hydrothermal synthesis of the nanorods have been discussed. Lead sulfide (PbS) nanorods with a high aspect ratio were prepared by a novel thioglycolic acid assisted hydrothermal method. X-ray diffraction and transmission electron microscopy revealed that the product was rod-like PbS with cubicrock-salt structure. Further characterizations by selected area electron diffraction and high-resolution transmission electron microscopy showed that the PbS nanorods were single crystalline in nature. Furthermore, the mechanismand critical factors for the hydrothermal synthesis of the nanorods have been discussed.