The present invention relates to the use of cationic polymers obtainable by free-radical copolymerization of a) 60 to 99 mol % of at least one 1-vinylimidazole monomer, b) 1 to 40 mol % of at least one free-radically polymerizable quaternizable monomer b1) or methacrylic acid b2) and c) 0 to 30 mol % of at least one further free-radically copolymerizable monomer different from a) and b) in hair cosmetic preparations.