Monoazodyestuffs free from water solubilizing moieties and which are useful in dyeing and printing polyester materials, mixtures of polyesters with natural materials or cellulose triacetate materials have the formula ##STR1## wherein X.sup.1 is nitro, cyano or methylsulphonyl and R.sup.1 is of the formula ##STR2## wherein Y.sup.1 is hydrogen, methyl or ethyl; Y.sup.2 is hydrogen, hydroxyl, alkanoyloxy having 1 to 4 carbon atoms in the alkanoyl moiety, or alkoxycarbonyloxy having 1 to 4 carbon atoms in the alkyl moiety, and said alkanoyloxy and said alkoxycarbonyloxy are each unsubstituted or substituted by alkoxy having 1 to 4 carbon atoms or phenoxy;Z is hydrogen, phenyl, cyano, hydroxyl, phenoxy, phenoxy substituted by alkyl having 1 to 4 carbon atoms, phenoxy substituted by alkoxy having 1 to 4 carbon atoms, halogen substituted phenoxy, alkoxycarbonyl having 1 to 4 carbon atoms in the alkoxy, alkoxycarbonyl having 1 to 4 alkoxy carbon atoms substituted by hydroxyl, alkoxycarbonyl having 1 to 4 carbon atoms in the alkoxy moiety substituted by alkoxy having 1 to 4 carbon atoms, phenoxy substituted alkoxycarbonyl having 1 to 4 alkoxy carbon atoms, phenyl substituted alkoxycarbonyl having 1 to 4 alkoxy carbon atoms, alkoxy having 1 to 4 carbon atoms, hydroxy substituted alkoxy having 1 to 4 carbon atoms, cyano substituted alkoxy having 1 to 4 alkoxy carbon atoms, alkoxy of 1 to 4 carbon atoms substituted by alkoxy having 1 to 4 carbon atoms, alkanoyloxy having 1 to 4 carbon atoms, phenoxy alkanoyloxy having 1 to 4 alkanoyl carbon atoms, alkanoyloxy having 1 to 4 carbon atoms substituted by alkoxy having 1 to 4 carbon atoms, alkoxycarbonyloxy having 1 to 4 carbon atoms in the alkyl moiety, alkoxycarbonyloxy having 1 to 4 alkyl carbon atoms substituted by alkoxy having 1 to 4 carbon atoms or phenoxy substituted alkoxycarbonyloxy having 1 to 4 alkyl carbon atoms;R.sup.2 is hydrogen, alkyl having 1 to 4 carbon atoms or alkoxy having 1 to 4 carbon atoms; andm is a number from 0 to 2.