Abstract: A flame-retardant polyphenylene ether resin composition comprising (I) 85 to 97% by weight of a resin consisting of (1) 20 to 90% by weight of a polyphenylene ether of the formula (A): ##STR1## where R.sub.1 and R.sub.2 are each alkyl of 1 to 4 carbon atoms and m is the degree of polymerization, and (2) 80 to 10% by weight of a styrene type polymer and (II) 3 to 15% by weight of at least one member of the group consisting of phosphorus-containing compounds of formula (B): ##STR2## where X is a hydrogen atom, a hydroxyl group, an amino group, a halogen atom, an alkyl group of 1 to 10 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, an alkylthio of 1 to 10 carbon atoms, an aryloxy of 6 of 10 carbon atoms or hydroxy substituted aryloxy of 6 to 10 carbon atoms, Y.sub.1 and Y.sub.2 are each an alkyl of 1 to 8 carbon atoms, an alkoxy of 1 to 8 carbon atoms or an aryl group, Z is an oxygen or sulfur atom, n and p are each an integer of 0 to 4 and q is an integer of 0 or 1.