A Fischer-Tropsch process for synthesizing hydrocarbons, by bringing a catalyst comprising a support and an active phase comprising a Group VIII metal into contact with a feedstock comprising synthesis gas, said catalyst being prepared according to the following steps: a) a porous support is provided; b) an organic compound containing oxygen and/or nitrogen is added to the porous support; c) a step of bringing said porous support into contact with a solution containing a salt of a precursor of the phase comprising a Group VIII metal is carried out; d) the porous support obtained at the end of step c) is dried; characterized in that step b) is carried out by bringing together said porous support and said organic compound under conditions of temperature, pressure and duration such that a fraction of said organic compound is transferred in the gaseous state to the porous support.