Cosmetic compositions comprising, in a cosmetically acceptable medium, at least one crosslinked methacrylic acid/C.sub.1-C.sub.4 alkyl acrylate copolymer, at least one oil chosen from synthetic oils, C.sub.3-C.sub.14 acid esters comprising in total less than 20 carbon atoms, and plant oils with a palmitoleic acid content of greater than or equal to 0.2% by weight of the oil. These compositions can be used for washing and/or conditioning keratin materials such as the hair or the skin.