Optical and energy storage materials based on semiconductors are of great interest today. The present report explains the semiconductor nanocomposite centered on highly transparent Poly(methyl methacrylate) (PMMA) matrix and Cadmium Sulphide (CdS) nano particles. The solid films of CdS:PMMA composite was prepared using simple and cost effective solution casting technique. The surface morphology and the presence of CdS particles in PMMA matrix was analysed using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectra (EDX). The size of the particles was analysed using Atomic Force Microscopy (AFM) and Transmission Electron Microscope (TEM) and they revealed the presence of nano sized particles. The narrow size distribution of particles was identified from TEM and AFM analysis. The transmittance of the CdS:PMMA nanocomposite solid films was found to be above 90%. The blue and green emission of CdS:PMMA nanocomposite solid films were observed from Photoluminescence (PL) spectra.