Flame-retardant thermoplastic molding compositions comprise A) at least one polyphenylene ether, andB) at least one vinylaromatic polymer, wherein the thermoplastic molding composition includesC) at least one oligomeric phosphorus compound as flame retardant andD) a mixture ofD.sub.1) at least one sterically hindered phenol andD.sub.2) at least one phosphonite as stabilizer,and are used to produce fibers, films and shaped articles.