The present invention relates to a cosmetic hair treatment process, especially for caring for and/or cleansing the hair, comprising:a step (i) of applying to said hair a “first” cosmetic composition, comprising one or more cationic surfactants, one or more silicones and one or more non-silicone fatty substances, and thena step (ii) of applying to said hair a “second” cosmetic composition, comprising one or more cationic surfactants, one or more cationic polymers with a cationic charge density of greater than or equal to 4 meq./g, and one or more organosilanes.Said process makes it possible especially to obtain conditioning that is both immediate and long-lasting.
