L-glutaminase has versatile applications in pharma and food industries. In pharmaceutical industry, L-glutaminase can be used as anti-oxidant and anti-cancer agent to treat Acute Lymphocytic Leukaemia (ALL). Whereas, in the food industry, L-glutaminase is used for acrylamide degradation, theanine production, flavour enhancer, soy sauce and many. The other applications include nitrogen metabolism and its use as biosensor in hybridoma technology. Both intra-cellular and extra-cellular L-glutaminases from wide range of sources were identified. Because of its diverse applications, there is a need to improve the production of L-glutaminase by enzyme engineering technology. Effect of recombination on L-glutaminase production was also reported. Researchers also confirmed the antitumor properties of L-glutaminase by conducting in vitro, in vivo and in silico studies. Bacillus sps. and Aspergillus sps. are the commercial producers of L-glutaminase. In this review, the applications, different sources of Lglutaminase, anti-cancer properties were discussed.