The paper presents the influence of oxygen on the properties of cadmium sulfide thin film included during the deposition of CdS film using chemical bath deposition. The structural, surface morphological and optical properties were studied and a comparative study is presented between CdS film deposited without oxygen and with oxygen. The deposition temperature was kept 70 degrees C for both the deposition sequence and the deposition time was 40 min. The film thickness obtained was nearly 100 nm for both the cases. The average transmission was nearly 80% for both sets of film. The band gap calculated from transmission data shows a significant increase in the band gap for the CdS film deposited with the inclusion of oxygen. The scanning electron microscope micrograph shows reduced pinholes for the film grown with oxygen. X-ray diffraction and Raman studies show better crystallinity for the CdS film grown with oxygen. The CdS film deposited in the presence of oxygen can be a better choice for cadmium telluride (CdTe) and copper indium gallium diselenide Cu(In,Ga)Se-2 based thin film solar cells. (C) 2012 Elsevier B.V. All rights reserved.