Two Streptomyces strains, M7a and M23, from a Brazilian forest soil were evaluated for the cellulase production of their supernatants after growth in a microcrystalline cellulose medium, using carboxymethylcellulose and filter paper as substrates at different temperatures and pH values. Endoglucanase and exoglucanase activities were compared to a commercial Trichoderma reesei cellulase using fluorogenic conjugated substrates. Similar specific activities were observed for the enzyme preparations of strain M23 and T. reesei. For M7a the activities were about seven times higher than those obtained for T. reesei. Extracellular or cell-associated cellobiase activities were not detected in both strains.