An attempt made for the selective production of C-2-C-4 olefins directly from the synthesis gas (CO + H-2) has led to the development of a dual catalyst system having a Fischer-Tropsch (K/Fe-Cu/AlOx) catalyst and cracking (H-ZSM-5) catalyst operate in consecutive dual reactors. The flow rate (space velocity) and H-2/CO molar ratio of the feed have been optimized for achieving higher CO conversions and olefin selectivities. The selectivity to C-2-C-4 olefins is further enhanced by optimizing the reaction temperature in the second reactor (cracking), where the product exhibited 51% selectivity to C-2-C-4 hydrocarbons rich in olefins (77%) with a stable time-on-stream performance in a studied period of 100 h.