Composition for washing keratin materials, comprising, in a cosmetically acceptable medium: i) at least one detergent surfactant; ii) at least one polyorganosiloxane with a viscosity of less than 0.1 m.sup.2.multidot.s.sup.-1 ; iii) at least one cationic polymer; and iv) at least one acrylic terpolymer consisting of a monomer (a) chosen from a C.sub.1 -C.sub.6 alkyl acrylate and a C.sub.1 -C.sub.6 alkyl methacrylate; of a monomer (b) chosen from a heterocyclic vinyl compound containing at least one nitrogen or sulphur atom, a (meth)acrylamide, a mono- or di(C.sub.1 -C.sub.4)alkylamino(C.sub.1 -C.sub.4)alkyl (meth)acrylate and a mono- or di(C.sub.1 -C.sub.4)alkylamino(C.sub.1 -C.sub.4)alkyl(meth)acrylamide; of a monomer (c) chosen from a urethane produced by reaction between a monoethylenic unsaturated isocyanate and a nonionic surfactant, a copolymerizable ethylenic surfactant monomer, a surfactant monomer of urea type, an allyl ether containing alkylenoxy groups and a nonionic monomer of urethane type.