Abstract: A particulate pre-reduction cobalt supported Fischer-Tropsch synthesis catalyst precursor which comprises a catalyst support impregnated with cobalt, is treated with a pure hydrogen reducing gas, at a first specific feed gas space velocity, SV1, and at a first heating rate, HR1, to obtain a partially reduced precursor. The support contains reducible cobalt oxide in a calcined state and having a formula-unit in which each mole of cobalt atoms is associated with more than 4/3 moles of oxygen atoms and displaying a reducible cobalt oxide specific surface area at least equal to that of Co3O4 spinel. The partially reduced precursor is then treated with a pure hydrogen reducing gas, at a second specific feed gas space velocity, SV2, and at a second heating rate, HR2, to obtain an activated supported Fischer-Tropsch catalyst, with SV2?SV1 and/or HR2?HR1; however, when SV2=SV1, HR2?HR1 and when HR2=HR1, SV2?SV1.