An antistatic polyester film having the excellent antistatic property and improved appearance of a coating layer, and a process for producing the same are disclosed. The antistatic polyester film comprises a polyester film having formed on at least one surface thereof an antistatic coating layer obtained by coating a coating liquid containing an organic-inorganic composite conductive sol (A) comprising colloidal particles of conductive oxide, having a primary particle size of 5 to 50 nm, and colloidal particles of a conductive polymer. This antistatic polyester film has excellent antistatic property, particularly excellent antistatic property under the low humidity environment, and therefore is useful in magnetic cards, magnetic disks, printing materials, graphic materials, photosensitive materials and the like.