Chitinases are ubiquitous class of extracellular enzymes, which have gained attention in the past few years due to their wide biotechnological applications. The effectiveness of conventional insecticides is increasingly compromised by the occurrence of resistance; thus, chitinase offers a potential alternative to the use of chemical fungicides. The thermostable enzymes from thermophilic microorganisms have numerous industrial, medical, environmental and biotechnological applications due to their high stability for temperature and pH. Thermomyces lanuginosus produced a large number of chitinases, of which chitinase I and II are successfully cloned and purified recently. Molecular dynamic simulations revealed that the stability of these enzymes are maintained even at higher temperature. In this review article we have focused on chitinases from different sources, mainly fungal chitinase of T. lanuginosus and its industrial application.