The promoting effect of Rh on Co/SiO2 Fischer-Tropsch catalysts was studied as well as on Ag-Co and Au-Co bimetallic catalysts. The Fischer-Tropsch synthesis (FTS) activity on the cobalt-based bimetallic catalysts followed an order of Rh-Co > Au-Co > Co > Ag-Co. Both Au-Co and Rh-Co catalysts showed an induction period of about 40 hr, during which the CO conversions increased significantly. The addition of a very small amount of Rh to Co/SiO2 increased the CO conversion, while the selectivity was not affected. Both the addition of Ag and Au resulted in a slightly lower selectivity to C5+ products. The selectivity to C5+ products on the Rh-Co catalysts increased with time during the induction period, and at the steady-state conditions, the product distributions were the same as on Co/SiO2.