A process for dyeing or treating textile fibre materials with foam, which process comprises applying to the textile fibre materials a foamed aqueous composition which, in addition to containing the dye (or fluorescent whitening agent) or the fabric finishing agent, contains a foamable system comprising water and(A) a fatty acid/alkanolamine reaction product or an alkylene oxide adduct of this reaction product andat least two of the following components(B) a fatty alcohol which is optionally mono-, di- or triethoxylated and which contains 8 to 22 carbon atoms in the fatty alcohol radical,(C) an adduct of 5 to 15 moles of ethylene oxide and 1 mole of a fatty alcohol or a fatty acid, each containing 8 to 22 carbon atoms, or 1 mole of an alkylphenol containing a total of 1 to 12 carbon atoms in the alkyl moiety,and(D) an acid ester, or a salt thereof, of a polyadduct of 2 to 15 moles of ethylene oxide and 1 mole of a fatty alcohol containing 8 to 22 carbon atoms.The composition is then applied to the textile fibre materials, which are subsequently subjected to a heat treatment, e.g. by thermofixation, in the temperature range from 120.degree. to 210.degree. C., or by steaming in the range from 100.degree. to 120.degree. C., with or without first drying them.