A simple route for preparation of aqueous colloidal solutions of cadmium sulfide nanoparticles with a narrow size distribution, showing a quantum confinement effect (Q-CdS), is described. A combination of the widely-used spin/dip coating techniques was utilised to deposit high optical quality Q-CdS films on indium tin oxide glass; film thickness can be varied from 50 to 200 nm. The results of optical and structural characterisation of the Q-CdS films with photoluminescence, light absorption and high resolution electron microscopy are presented and discussed.