Primary, secondary and tertiary alkyl halides (Cl, Br, I) were adsorbed onto zeolite NaX at room temperature. The products formed were analyzed using solid-state 13C, liquid 1H NMR and infrared spectroscopy (IR). Primary chloro and bromo undergo both dehalogenation and dehydrohalogenation to form framework alkoxy and olefins respectively while the secondary counterparts, predominantly formed olefins. All the primary iodo compounds formed framework alkoxy while the secondary formed mixtures of framework alkoxy and olefins. No reaction was observed with all the three tertiary halides (Cl, Br and I) studied. The nature of the halogen and its position in the chain were observed to be the determining factor on product selectivity. Olefin formation commenced with halopropane. In agreement with the theoretical predictions that reactions of alkyl halides with zeolites involve bimolecular mechanism [N. Rosenbach, C.J.A. Mota, Journal of Molecular Structure: 731 (2005) 157], the observed products (framework alkoxy and olefins) were formed via a non-rearranged mechanism, a characteristic of bimolecular mechanism. In zeolite, a higher legioselectivity towards internal olefins with yields greater than 96% was observed with the secondary alkyl halides.