The present invention relates to a composition for washing and conditioning keratin materials, comprising, in a physiologically acceptable medium:from 3% to 50% by weight, relative to the total weight of the composition, of one or more anionic surfactants,one or more C10-C30 liquid alcohols chosen from branched and/or unsaturated C10-C30 alcohols, andone or more nonionic associative polymers.The invention also relates to the use of the said composition for washing and conditioning keratin materials, and to a process for washing and conditioning keratin materials using it.