The present invention relates to a process for sulfurizing a hydrocarbon treatment catalyst, comprising: at least a first step of depositing, on the surface of the catalyst, one or more sulfurization auxiliaries of formula (I): and at least a second step, carried out after the first step, of placing the catalyst in contact with a sulfur-containing gaseous mixture containing hydrogen and a sulfur compound. This process does not comprise the deposit of any carbon sources other than the auxiliary of formula (I).