The simultaneous production of endoglucanase and beta-glucosidase by Fusarium oxysporum was investigated in submerged culture Consecutive optimization of growth conditions resulted in the correction of large activity differences, observed during production of enzymes, and substantially enhanced low enzyme yields At optimum growth conditions yields as high as 1650 and 232 U per g of carbon source of endoglucanase and beta-glucosidase were obtained respectively competing favourably with those reported for microorganisms grown on the same carbon source. The most important kinetic characteristics of the enzymes were the high temperature optima of endoglucanase (60 degrees C) and beta-glucosidase (65 degrees C) and the exceptionally high thermostability of endoglucanase. Tire latter enzyme retained 50% of the activity at pH 5.0 after approximately 6.5 h at 70 degrees C.