Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-ex-change chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme ex-hibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of K m for oxa-late and V max for the enzyme reaction were 0.015 M and 30 mmol min -1, respectively.