Abstract : Polypyrrole microcapsules (prepared via the template method) were used for immobilization of both enzymatic and chemical catalytic systems. Enzymes immobilized include glucose oxidase, catalase, trypsin, subtilisin, and alcohol dehydrogenase. The chemical catalytic system investigated consisted of immobilized Pd nanoparticles for catalysis of hydrogen peroxide decomposition. Microcapsules loaded with glucose oxidase (GOD) were found to have higher enzymatic activity than GOD-loaded thin films, a competing encapsulation method. Trypsin was used to explore the possible leakage of small proteins from the capsules; no leakage was observed. Subtilisin was used to show that these microcapsules can be used in non-aqueous solvents. The effect of capsule wall thickness on the rate of enzymatic reaction was also explored.