Abstract: Cationic polyazo dyestuffs which can be obtained by reacting diaminobenzene derivatives of the general formula ##STR1## wherein R represents hydrogen, C.sub.1 - to C.sub.4 -alkyl, C.sub.1 - to C.sub.4 -alkoxy or halogen,if appropriate in a mixture with up to 30% of aromatic monoamines of the formula ##STR2## wherein R.sup.2 represents hydrogen, C.sub.1 - to C.sub.4 -alkyl, C.sub.1 - to C.sub.4 -alkoxy, halogen or C.sub.1 - to C.sub.4 -acylamino and n represents 1 to 3,with 0.5 to 0.75 mole of a salt or ester of nitrous acid per mole of diamine and then with 1 to 4 moles of an alkylene oxide of the formula ##STR3## wherein R.sup.3 represents hydrogen or an optionally hydroxyl-, alkoxy- or halogen-substituted C.sub.1 - to C.sub.4 -alkyl radical,are used--preferably in the form of their solutions--for dyeing paper, leather and anionically modified synthetic fibres.