AbstractA new method based on the inversion of a relation derived by Krathy, and thereby allowing the determination of the orientation distribution function of amorphous polymers by Wide Angle X‐Ray Scattering (WAXS), is described. With a simple approximation, in many cases disturbing intramolecular scattering can be separated from the measured azimuthal intensity distribution along the first maximum of the amorphous halo. For oriented amorphous poly(ethylene terephthalate), the 2nd and 4th moments of the determined orientation distribution functions agree very well with those from birefringence and spectroscopic measurements. The method is not applicable to partially crystalling polymers, because the approximation for intramolecular scattering does no longer hold. Finally, the intrinsic birefringence of bisphenol‐A‐polycarbonate was determined by this method to be 0,236 ±