Abstract: Solid dyestuff formulations having excellent dyebath stability are obtained in an economical manner by mixing a water-insoluble textile dyestuff with a dispersant and a carboxyl-containing copolymer of(a) an .alpha.,.beta.-ethylenically unsaturated monocarboxylic acid,(b) a non-basic ester of an .alpha.,.beta.-ethylenically unsaturated monocarboxylic acid, and(c) an unsaturated aliphatic or aromatic hydrocarbon or acrylonitrile,bead-milling the mixture down to a particle size of, preferably, 1-2.mu., and then spray-drying the ground mixture. If desired the dispersant can also be added during the synthesis of the dyestuff, as a consequence of which early addition the milling process can be dispensed with.