Wide‐line nuclear magnetic resonance (NMR) studies have been made as a function of temperature and the angle between the stretch direction and the magnetic field on one‐way stretched poly (ethylene terephthalate) film. The data obtained were consistent with a structural model, the important features of which are the directions of the lines between interacting methylene and aromatic protons relative to the stretch direction. Evidence for planar orientation in one‐way stretched poly (ethylene terephthalate) film was obtained from wide‐line NMR data which were taken as a function of the angle between the normal to the film surface and the magnetic field. A difference of approximately 25°C has been observed in the temperature at which the sharp component appears in annealed, unoriented poly (ethylene terephthalate) film and powder phase material from the solid‐phase buildup reaction. This difference is explained as being due to a difference in the degree of crystalline perfection.