A base film for a photographic film, which (A) consists essentially of polyethylene-2,6-naphthalenedicarboxylate containing naphthoic acid unit in an amount, in terms of methyl naphthoate, of 2 to 1,000 ppm, (B) has a light transmittance, T.sub.400, of at least 95%/cm at a wavelength of 400 nm when a solution of 10 mg/ml of the polyethylene-2,6-naphthalenedicarboxylate in a hexafluoroisopropanol/chloroform mixed solvent having a hexafluoroisopropanol/chloroform weight ratio of 2/3 is measured, (C) has a yellow index Y.sub.ID of at most S, and (D) has a haze value of 2.0% or less.