An encapsulated Mn(III)-salen complex in NaY was synthesized and characterized, and the catalytic behaviour of the complex was evaluated by the oxidation of styrene. The encapsulation was achieved by two different methodologies designated as the flexible ligand method (A) and the method of in situ complex synthesis (B). The characterizations of the free complex as well as the catalysts with and without the complex were performed by powder X-ray diffraction, scanning electron microscopy, chemical analysis and FT-IR spectroscopy. Both prepared catalysts are active in the oxidation of styrene in the presence of tert-butyl hydroperoxide (tBuOOH) and lead to styrene epoxide and benzaldehyde. The localization of the complex in zeolite plays an important role in the catalytic activity of these heterogeneous catalysts.