A set of zeolite-supported Ru catalysts was prepared from Ru3(CO)12 using zeolites NaX, NaY, KL and NaMordenite. These catalysts were characterized and studied under Fischer-Tropsch conditions in order to determine their unique properties and the effect of the zeolite support. For comparison, a catalyst using SiO2 as support was also used. Ru3(CO)12 did not appear to be able to diffuse into NaX. Overall, the best catalyst in terms of high Ru dispersion, low methane selectivity and high olefin selectivity was Ru/NaY. The type of zeolite used as the support had a strong effect on methane selectivity. This method of preparation, compared to the ion-exchange method, is much superior in producing low yields of methane and high yields of olefins.