Cadmium sulfide (CdS) one dimensional (1D) nanoaystals were prepared using a polyethylene glycol (PEG) assisted hydrothermal synthesis. X-ray diffraction result confirms that the nanorods are of hexagonal structure and the selected area electron diffraction (SAED) identifies the single crystalline nature of the sample. The sample was systematically characterized by UV-vis absorption, photoluminescence (PL) spectrum, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermal analysis. The UV-vis absorption spectrum indicates the narrow size distribution of the CdS nanorods. The absorption band edge is seen shifted to 505 nm than the bulk material and the corresponding band gap is found to be 2.45 eV. The PL emission peak is detected around 550 nm. From SEM and EDX analysis, the morphology of the aggregates and the composition of the obtained product are identified. The TEM micrographs indicate that the CdS nanorods exhibit well defined morphology and high crystalline quality with narrow size distribution of lengths and widths. The TG/DTA traces of the nanopowder show four major stages of weight loss. (C) 2010 Elsevier B.V. All rights reserved.