Zinc sulphide nanoparticles have been synthesized in silica matrix using sol-gel method. It is observed that silica could be loaded with zinc sulphide over a very wide range of concentration without changing the nanoparticle size. A strongly luminescent zinc sulphide-silica composite, thermally stable even upto similar to 700 degreesC was thus obtained. Several techniques like UV absorption, photoluminescence, x-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetry and photoelectron spectroscopy have been performed to analyse the ZnS-silica composites.