Co-precipitated Fe–Co–Ni catalysts were tested for production of light olefins via Fischer–Tropsch synthesis. The effects of different supports such as Al 2 O 3 , SiO 2 , TiO 2 and MgO and subsequently the effect of optimum support loading and also the effect of different promoters including Li, Cs, K, Rb and Ru on the catalytic performance and structure of Fe–Co–Ni catalyst were investigated. It was found that the Fe–Co–Ni catalyst containing 10 wt% MgO has shown the better catalytic performance for FTS. The yield of methane, ethylene, propylene and C 4 + olefins were calculated and reported. Characterization of the catalyst precursors and calcined samples was carried out using XRD, SEM, EDS and BET.