A polycarbonate resin composition which has excellent flame retardancy, even when containing neither any phosphorus compound flame retardant nor any halogenated flame retardant, and which is highly reflective and has light-shutting properties and excellent thermal stability. The polycarbonate resin composition comprises 5 to 98 parts by weight of a polycarbonate/polyorganosiloxane copolymer, 0 to 93 parts by weight of a polycarbonate resin, 2 to 50 parts by weight of titanium oxide, 0 to 1.0 parts by weight of a fibril-forming polytetrafluoroethylene, and 0.05 to 2.0 parts by weight of an organosiloxane, the sum of the ingredients (A), (B), and (C) is 100 parts by weight.