Pure Cadmium Sulphide (CdS) thin films have been coated on glass substrate at 400°C by spray pyrolysis (SP) technique using different precursors (Cadmium nitrate-A, Cadmium acetate-B and Cadmium chloride-C). Pure CdS thin films were characterized by various techniques such as X-ray diffraction, SEM and optical studies. X-ray diffraction measurements show that CdS thin films belong to the cubic crystal structure with preferential orientation along (1 1 1) direction. The average crystallite size (D) of CdS thin films with different precursors are 48 nm (A), 29 nm (B) and 27 nm (C) respectively. The average dislocation density (δ) and stacking fault (SF) of CdS thin films are 5.93x1015 lines/m2 (A), 13.71x1015 lines/m2 (B), 16.73x1015 lines/m2 (C) and 0.7996 Å (A), 1.3367 Å (B), 1.3325 Å (C). The surface morphology of the thin films was determined by scanning electron microscopy (SEM). The optical energy band gap of thin films is 2.43 eV (A), 2.31 eV (B) and 2.16 eV (C). The luminescence spectrum shows a strong emission peak at 518 nm (A), 521 nm (B), 525 nm (C). We can postulate that our fabricated CdS thin films will be useful for optoelectronic devices.