Flame-retardant thermoplastic moulding compositions containing an aromatic polycarbonate or polyestercarbonate, a graft polymer, a thermoplastic vinyl copolymer, a fluorinated polyolefin, 0.5 to 20 parts by weight of at least one phosphorus compound of general formula (I) ##STR1## wherein the average degree of polycondensation N of component D is always >5, a very finely divided inorganic powder with an average diameter of 0.1 to 200 nm and/or a monophosphorus compound, wherein the sum of the parts by weight of all the components is 100.