Abstract: A flame retardant thermoplastic composition having excellent physical properties comprises about 50 to about 90 wt. % of a polycarbonate resin; from about 5 to about 35 wt. % of an impact modifier; about 0.5 to about 30 wt. % of a polysiloxane-polycarbonate copolymer comprising about 8 to about 30 wt. % polydimethylsiloxane units or the equivalent molar amount of other diorganosiloxane units; and about 0.5 to about 20 wt. % of a phosphorus-containing flame retardant, each based on the total combined weight of the thermoplastic composition, exclusive of any filler. In one embodiment a sample of the thermoplastic composition having a thickness of 2.5 mm (±10%) achieves a UL94 5VA rating. Thinner samples may also achieve this rating. The compositions are useful in forming flame retardant thin-walled articles.