An aqueous or aqueous-alcoholic crease-resistant formulation comprising a cationic surfactant (CSA), for the treatment after washing in aqueous or aqueous-alcoholic medium of articles made of textile fibers, said formulation also comprising a soluble or dispersible copolymer of controlled architecture (C) that is compatible with the surfactant (CSA) at the pH of said formulation and at the pH of use of said formulation, and comprising at least one nonionic hydrophobic organic polymer block B, and at least one ionic or ionizable organic polymer block A, the copolymer (C) making possible to give said articles properties of crease resistance and/or of ease of ironing.