Two xylanases (I and II) out of several extracellular xylanases produced by the thermophilic fungus Chaetomium thermophile var. coprophile were purified to homogeneity by a combination of ion exchange and gel filtration chromatographic procedures. They had molecular weights of 26 000 (xylanase I) and 7000 (xylanase II). The temperature optima for xylanase I and II were 70 and 60 °C, and they were optimally active at pH 4.8–6.4 and 5.4–6.0, respectively. Xylanase I was found to be comparatively more stable than xylanase II at higher temperatures. Amino acid composition indicated that xylanase I contained high amounts of glycine, threonine, and low amounts of histidine and sulphur-containing amino acids. Each enzyme released different hydrolysis products from larch wood xylan. Xylanase I produced mainly xylobiose and xylotriose whereas xylanase II produced mainly xylobiose.Key words: Xylanase, enzyme purification, characterization, Chaetomium thermophile.