A monoazo compound of the following formula, ##STR1## wherein X is a hydrogen or halogen atom, or a C.sub.1-4 alkyl, C.sub.1-4 alkoxy, C.sub.1-4 alkylsulfonyl, C.sub.1-4 alkylcarbonyl, C.sub.1-4 alkoxycarbonyl, nitro, cyano or trifluoromethyl group, Y is a hydrogen or chlorine atom or a methyl or acylamino group, and Z is a hydrogen or chlorine atom or a methyl, methoxy or ethoxy group, which is useful for dyeing or printing hydrophobic fibers with superior level dyeing and build-up properties to give dyed products of a brilliant color superior in fastness properties.