Thermophilic bacteria that can produce cellulase as well as utilise agro-waste biomass have a high potential for developing thermostable cellulase required in the biofuel industry. In this work, the Central Composite Design (CCD) was adopted to maximize the production of cellulase by cultures of thermophilic Bacillus sp SMIA-2 containing sugarcane, corn steep liquor and passion fruit rind flour, as an alternative to the conventional rich medium. The conditions which favored higher enzyme activities were when lower concentrations of PFRF (3.225% w/v) were used in combination with either higher or lower concentrations of SCB and CSL.