Abstract: The present invention relates to a polybutylene terephthalate resin composition having excellent heat resistance properties and high toughness, comprising 85 to 99.5 parts by mass of a polybutylene terephthalate resin (A) having an intrinsic viscosity (IV) of 1.0 to 1.3 dl/g, 0 to 13 parts by mass of a polyester elastomer (B ), and 0.05 to 2 parts by mass of a talc (C) having an average particle size of 5 ?m or less, based on 100 parts by mass in total of components (A), (B) and (C), wherein in the case where the polyester elastomer (B) is contained, the mass ratio of hard segment/soft segment constituting the polyester elastomer (B) is 85/15 to 50/50.