Abstract: A process for the regeneration of deactivated catalyst from a Fischer-Tropsch synthesis reactor, the catalyst being a supported cobalt catalyst. The process comprises the following steps: a withdrawal step, in which a portion of deactivated catalyst together with liquid hydrocarbon is withdrawn from the reactor; a concentration step, in which the concentration of the catalyst in the liquid hydrocarbon is increased; a calcination step, in which the deactivated catalyst composition is subjected to an oxidizing gas to oxidize carbonaceous material contained in the deactivated catalyst in to gaseous oxides of the components of the carbonaceous material; and a reactivation step, in which the deactivated catalyst composition is reactivated to produced a regenerated catalyst.