Polarized Raman spectroscopy was used to analyze uniaxially oriented fibers of poly(ethylene terephthalate) (PET) fibers. The second-order and fourth-order Legendre polynomials of the orientation distribution function of the 1030-cm(-1) vibrational band were determined to be zero for samples of low-to-moderate orientation. Because this band was assigned to the gauche conformation of the ethylene glycol unit, the orientation of the gauche configuration of ethylene glycol units in PET for PET of low-to-moderate orientation was random. This was consistent with the assumptions used by Ward and coworkers. (C) 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42:47-52,2004.