A biaxially oriented polyester film having excellent scratch resistance and chipping resistance by the inclusion of particles (A) having an average primary particle diameter of 5-300 nm, an average degree of aggregation of 5-100 and a Mohs' hardness of 6-10 by the content of 0.01-5 wt. %. The scratch resistance and chipping resistance of the film can be further increased by the inclusion of particles (B) having an average particle diameter of 0.3-3 .mu.m, a Mohs' hardness smaller than that of particles (A) and/or non-incorporated particles.