Effect of laser flux density on the structural quality and optical properties of Zn0.6Cd0.4S thin films synthesized by ultraviolet pulsed laser deposition have been studied. The stoichiometric composition of this alloy was estimated using lattice constant calculated via XRD data. Surface morphology of the samples was examined using AFM. Optical properties were studied at room temperature by transmittance, absorbance, and photoluminescence measurements. Studies revealed that there is an improvement in the structural quality with increasing the laser flux density in some range. However, too high laser flux density could lead to the degradation in structural quality of thin film. It was observed from the PL data that with increase in laser flux density there is a decrease in the band gap. Transmission data shows a transmittance of more than 70% in the visible region. TEM investigation of the samples reveals that the particles are spherical in shape with average diameter of 15 nm. © 2009 Elsevier B.V. All rights reserved.