CuInS2 thin films were deposited by chemical spray of aqueous solutions containing CuCl2, InCl3 and thiourea at substrate temperature of 250 degrees C in air and subjected to annealing at 530 degrees C in H2S atmosphere. Structure and composition before and after annealing were studied by XRD, EDS, XPS and Raman spectroscopy. As-sprayed films were low-crystalline, showed uniform distribution of elements in film thickness and no oxygen content. For the CuInS2 films deposited from the solutions with [Cu2+]/[In3+] = 1.0 and 1.1, H2S treatment for 30 min increased the chalcopyrite content up to 73% and 51%, respectively. CuXS phase in sprayed CIS films promotes the crystallite growth but retards the formation of chalcopyrite phase during H2S treatment. (C) 2010 Elsevier B.V. All rights reserved.