A thermoplastic resin composition which has a melt flow rate of 8 to 15 g/10 min and a flexural modulus at 23°C of 20,000 kg/cm 2 or more and which comprises (A) 60 to 76% by weight of a specific crystalline polypropylene in which the propylene homopolymer portion has a Q value of 3.0 to 5.0, an istactic pentad fraction of 0.975 or more and an intrinsic viscosity [η] of 1.20 to 1.40 dl/g as measured at 135°C in tetralin, (B) 2 to 10% by weight of an ethylene-butene-1 copolymer rubber, (C) 2 to 10% by weight of an ethylene-propylene copolymer rubber and (D) 16 to 25% by weight of talc having an average particle diameter of 4 µm or less, and an injection molded article of the thermoplastic resin composition, said thermoplastic resin composition satisfying the impact strength and rigidity required as a material for an instrumental panel and having a short molding cycle and good surface quality.