Thermophilic microorganisms are ubiquitous in nature growing on wide varieties of substrates due to the secretion of thermostable enzymes which are useful in various biotechnological industries. Thermophiles produced high titres of cellulases and xylanases in both solid-state and submerged fermentations regulated by various physico-chemical factors. Purification of these hydrolytic enzymes has been carried out by combination of various chromatographic techniques to study their biochemical properties. The majority of xylanases and cellulases from thermophiles have optimum pH in the range of 4.5-9.0 with temperature optima at 50 to 80 degrees C. The molecular masses of xylanases and cellulases from thermophiles ranged from 21 to 78 kDa and 30-250 kDa, respectively. Genetic engineering studies have improved their production and properties for commercial applications. Thermostable enzymes from thermophiles have been utilized in production of different biofuels like ethanol, butanol, 2,3-butanediol and hydrogen. This review describes the production, characteristics, genetic engineering and potential biotechnological applications of cellulolytic and xylanolytic enzymes of thermophiles. (C) 2018 Elsevier Ltd. All rights reserved.