The subject of the present invention is a process for bleaching keratin fibres consisting in applying to said fibres a bleaching composition resulting from the mixing: &mdashof at least one anhydrous composition A comprising at least one peroxygenated salt, &mdashof at least one aqueous composition B comprising at least one basifying agent, and &mdashof at least one composition C comprising at least one oxidizing agent and at least 3% by weight of fatty substance relative to the total weight of the composition C, said bleaching composition comprising at least 10% by weight of fatty substance.
