Anionic dyestuffs which contain, as the cation an ammonium ion of the formula ##STR1## wherein R.sub.1 and R.sub.2 independently of one another denote hydrogen, C.sub.1 -C.sub.6 -alkyl which is optionally substituted by hydroxyl, cyclopentyl, cyclohexyl or phenyl, naphthyl or benzyl which are optionally substituted by halogen, C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -alkoxy, or one of the radicals --(CH.sub.2 --X--O).sub.n --H, [-alkylene-N (R.sub.3 --].sub.P --R.sub.3 or -arylene-N (R.sub.3)--(CH.sub.2 --X--O).sub.n --H or denotes, together with the nitrogen atom, a 5-membered to 7-membered heterocyclic radical,R.sub.3 denotes hydrogen, C.sub.1 -C.sub.6 -alkyl which is optionally substituted by OH, cyclopentyl, cyclohexyl or phenyl, naphthyl or benzyl which are optionally substituted by halogen, C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -alkoxy, or the radical --(CH.sub.2 --X--O).sub.n --H,X represents ##STR2## n represents the numbers 1-10, preferably 1-5, and P REPRESENTS THE NUMBERS 1-4Are readily soluble in water.