The present invention relates to a cosmetic composition comprising: (a) one or more antidandruff agents, and (b) one or more amphoteric polymers comprising a repetition of: (i) one or more units derived from a monomer of (meth)acrylamide type, (ii) one or more units derived from a monomer of (meth)acrylamidoalkyltrialkylammonium type, (iii) one or more units derived from an acidic monomer of (meth)acrylic acid type. The invention also relates to a cosmetic process for treating keratin fibres using such a composition, and to a cosmetic use for facilitating the styling and/or for improving the suppleness, smoothness and/or disentangling of the hair.