Stratospheric conditions of direct photodissociation of molecular oxygen by solar radiation in the 202-242 nm wavelength range have been determined after introduction of the more recent aeronomic parameters: solar irradiances ofSUSIM from Spacelab 2, O2 absorption cross-sections, molecular scattering cross-sections and O3 absorption cross-sections. The O2 photodissociation frequency has a maximum of 5.8 × 10-10 s-1, becomes about 5.3 × 10-10 s-1 at the stratopause and reaches an isophotolytic level at 5 × 10-12 s-1 for any variation in the adopted O2 absorption cross-section. The accuracy of the O3 absorption cross-section should be better than ± 2.5%, particularly in the 202-220 nm wavelength range to reduce the errors in the O2 photodissociation rates at low stratospheric levels to less than ± 10%.