Xylanase has been increasingly forthcoming in recent years because of their possible involvement in numerous industrial processes including bioconversion of lignocellulose derived sugars in to fuels, processing food and the paper and fiber industries. Edible mushrooms are emerging as important source of xylanolytic enzymes and this study has concentrated to produce and characterize xylanases by Pleurotus eryngii. The crude enzyme was characterized on the basis of various parameters such as incubation time, substrate specificity, substrate concentration, enzyme volume, buffer, pH, pH stability, temperature, temperature stability, and effect of various metal ions or compounds. The xylanase activity was noted maximum at 15 minutes of incubation time, 2.0% xylan and 0.5 ml enzyme volume. The highest enzyme activity was found at pH 4.5, whereas xylanase exhibited maximum stability in the range of pH 4.0 to 10.0. The maximum xylanase activity was noted at 60°C, while enzyme was most active and retains more than 40% activity at 90°C within 10 minutes of incubation. ZnCl₂ (10mM) stimulated the xylanase activity as compare to other metal ions or compounds. It is concluded that Pleurotus eryngii is capable to produce pH stable and thermostable xylanase for industrial purposes.