Water-soluble azo compounds having useful fiber-reactive dye properties conforming to the general formula ##STR1## in which: A is phenylene which may be substituted or unsubstituted, or is a radical of the formula ##STR2## in which W is a direct bond or a radical of the formula --CH.dbd.CH-- or --NH--CO--NH-- and R* denotes hydrogen, nitro, sulfo, carboxy, methyl, ethyl, methoxy or ethoxy;n is the number zero or 1;B is a radical of the formula ##STR3## where R is equal to carboxy or carbamoyl; M is hydrogen or an alkali metal; andK is one of five radicals described in the specification, each of which contains a fiber-reactive group.These azo compounds produce fast dyeings on carboxamido- and/or hydroxy-containing materials, in particular cellulose fibers. On cellulose, fast dyeings are also obtained in a weakly acid to neutral medium, for example together with disperse dyes for dyeing a polyester fiber portion.