Copper indium disulphide (CuInS 2 ), is a good absorber material for photovoltaic applications. In this work, CuInS 2 is deposited by chemical spray pyrolysis on heated glass substrates. It is observed that the film growth temperature and the ion ratio Cu/In affects the structural and optical properties of CuInS 2 thin films. This paper presents the effect of temperature on the growth (for the ion ratio Cu/In=1.25), optical and photoluminescence properties of sprayed CuInS 2 films. The XRD patterns confirm the well defined single phase composition of CuInS 2 films grown from 300 to 350 1C (at Cu/In=1.25) as optimum temperature for depositing well defined crystallites along (1 1 2) oriented CuInS 2 thin films with chalcopyrite structure. D 2d point symmetry group is associated with the CuInS 2 crystallites with energy gap of 1.53 eV at room temperature. The chemical nature and the presence of additional phases are discussed based on the EDAX measurements. The absorption coefficient of sprayed CuInS 2 films is found to be in the order of 10 5 -10 6 cm ร 1 in the UV-visible region and the optical band gap decreases with increase in temperature. Defects-related photoluminescence properties are also discussed. CuInS 2 polycrystalline films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of copper (II) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates.