Bacillus sp SMIA-2 a thermophilic, aerobic, spore-forming bacterium, is capable of utilizing the organic matter consisting of complex mixtures typical of most wastes and efficiently produces several extracellular hydrolyzing enzymes of biotechnological importance. In this work, the cellulase production by Bacillus sp SMIA-2 grown in cultures containing sugarcane bagasse treated (SCB) with alkali was optimized using an experimental design approach. The independent variables used in the design were SCB concentration, corn steep liquor (CSL) concentration and culture time. Dependent variables were the activities of carboxymethylcellulase (CMCase) and filter paper activity (FPase). After graphical and numerical optimization procedure, the CMCase activity reached its maximum value after 120 h fermentation, in a medium containing 0.63 gL-1 of both, SCB and CSL. Regarding to FPase, the maximum enzyme activity was reached with 4.0 gL-1 SCB and 4.0 gL-1 CSL, after 197 h of culture time.