A fire-extinguisher composition comprising a blend of at least one member selected from the group consisting of protein and protein decomposition products, at least one liquid polyhydroxy compound or an aqueous solution of at least one polyhydroxy compound, and at least one halogenated hydrocarbon. The composition can easily be emulsified or dispersed in water and exhibits a high retention of its fire-extinguishing ability, a satisfactory secondary fire-extinguishing ability, and a foaming ability sufficient to make a foaming device unnecessary.