Poly (methyl methacrylate) (PMMA)-starch composites were prepared by emulsion polymerization technique for L-asparaginase (L-ASNase) immobilization as highly activated support. The hydroxide groups on the prepared composites offer a very simple, mild and firm combination for enzyme immobilization. The pure PMMA and PMMA-starch composites were characterized as structural, thermal and morphological. PMMA-starch composites were found to have better thermal stability and more hydrophilic character than pure PMMA. L-ASNase was immobilized onto PMMA-starch composites contained the different ratio of starch (1, 3, 5, and 10 wt %). Immobilized L-ASNase showed better performance as compared to the native enzyme in terms of thermal stability and pH. K-m value of immobilized enzyme decreased approximately eightfold compared with the native enzyme. In addition to, immobilized L-ASNase was found to retain 60% of activity after 1-month storage period at 4 degrees C. Therefore, PMMA-starch composites can be provided more advantageous in terms of enzymatic affinity, thermal, pH and storage stability as L-ASNase immobilization matrix. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43421.