High quality sensor grade nanostructured thin films of multicomponent semiconducting oxide sensors with superior sensitivity for monitoring trace levels of pollutant gases like NOx, NH3, H2 etc., in the ambient have been deposited by pulsed laser deposition technique. In-situ growth carried out at relatively lower temperatures yield granular films composed of nanocrystals of the desired crystallographic phase which otherwise would require high temperatures to stabilize. At some specific deposition conditions, growth of thin films containing uniform sized nano-grains with optimum inter-granular connectivity can be readily achieved. Here, we present the superior sensing properties of the sensor grade films of selected materials and bring out the unique characteristics of pulsed laser deposition technique for exploratory research in nano-structured thin films of materials not amenable to conventional synthetic routes.