Membrane technology had been used extensively for the separation of different gases. Among different types of membranes, mixed matrix membranes and comprising inorganic fillers in the polymer matrix, have gained enormous importance in recent years due to the synergic benefits from both the components. Among different inorganic fillers, silica is the most extensively used. In the present paper, a comprehensive discussion is given on the available research works in nanosilica-polymer composite based mixed matrix membranes. The discussion includes different fabrication methods as well as different characterization techniques and applications for the system.