To provide a polyester resin composition having excellent physical properties such as heat resistance and surface smoothness, and to provide a plastic molded article.

The polyester resin composition comprises a polybutylene terephthalate base resin, and a 10-50 parts by mass of a polyethylene terephthalate glycol resin, 0.1-10 parts by mass of an inorganic filler and 0.01-5 parts by mass of resin stabilizer as the basis for 100 parts by mass of a polybutylene terephthalate base resin. The plastic molded article is produced using the polyester resin composition.