<P>The aim of this study was to assess the mixed combination of coffee pulp waste (CPW) and pineapple waste (PW) residues for cellulase production using newly isolated <I>Acinetobacter</I> sp. TSK-MASC in solid state fermentation. Response surface methodology based Box-Behnken design (BBD) was employed to optimize variables such as pH, incubation time, concentrations of CPW and PW. The BBD design investigation showed a sound adjustment of the quadratic model with the experimental statistics. Statistics based 3-D plots were generated to evaluate the changes in the response surface and to understand the relationship between the enzyme yield and culture parameters. The higher production (888 U mL<SUP>−1</SUP>) was achieved after 60 h of incubation with 3.0 g L<SUP>−1</SUP> of CPW and PW at pH 7.0.</P>