[en] Zinc doped Cadmium Sulphide thin films are prepared by the conventional spray pyrolysis method at different (0.002 M to 0.01 M) Zinc concentrations. X-Ray Diffraction profile of the developed films confirms hexagonal wurtzite structure with the preferred orientation along the along the c-axis (002) direction. All the films show nanocrystallinity with hexagonal wurtzite structure.The average grain size evaluated from the XRD data lies between 300 nm and 200 nm. The lattice constant a and c evaluated from the XRD data are 4.1072 and 6.668 respectively and is well in agreement with the standard values. The influence of substrate temperature on the other structural parameters viz., texture coefficient and standard deviation have investigated and reported. The higher standard deviation value at low substrate temperature is attributed to the adsorption – desorption phenomena and the saturation of standard deviation values at high substrate temperature is due to homogeneous nucleation. Transmittance and absorbance data was obtained by using UV-Vis spectrometer. Transmittance of 80% is found beyond the 800 nm wavelength. Optical band gaps calculated from these data show a gradual decrease in 2.25 eV and 2.75 eV with a gradual increase in different zinc content 0.002M to 0.01M. All these results confirm the effect of various concentrations on zinc content CdS thin films. (author)