Rod-like and slice nanocrystalline Bi2S3 thin films have been prepared by the asynchronous-pulse ultrasonic spray pyrolysis (APUSP) technique from Bi(NO3)(3) and thiourea at relatively low temperature without any complexing agent or stabilizing agent. The growth of Bi2S3 thin films can be controlled successfully by the improved APUSP method. Characterization of the films has been carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. XRD and XPS analysis have shown that films were pure stoichiometric Bi2S3 (Bismuthinite, a = 1.1149, b = 1.1304, c = 0.3981 nm) and polycrystalline. Uniform and rodlike particles with diameters of 100-120 nm and length of up to 1.5 mum have been observed in the films by SEM. SEM studies revealed that the orientation of crystallites in the films depends on the property of substrates. It is shown that there is a difference in Raman shift between the slice (252 cm(-1)) and rod-like (238 and 266 cm(-1)) samples. (C) 2002 Elsevier Science B.V. All rights reserved.