The invention relates to cosmetic compositions comprising, in a cosmetically acceptable medium, at least one conditioner chosen from poly-&agr;-olefins, fluoro oils, fluoro waxes, fluoro gums, carboxylic acid esters, cationic polymers, silicones that are insoluble in the medium, mineral, plant or animal oils and at least one polyoxyalkylenated aminosilicone of (AB)n type, A being a polysiloxane block and B being a polyoxyalkylenated block containing at least one amine group. This combination gives considerably better cosmetic properties (smoothness, softness) than the properties obtained with one or other of the constituents used alone. These compositions are used to wash and/or condition the hair.