Molecular orientation along the depth of poly(propylene) (PP) and PP nanocomposite samples was analyzed by using confocal Raman microspectroscopy. The injection process led to a chain orientation that is higher on the surface of the samples. Residual stresses were relaxed through an annealing treatment, resulting in an increase of the molecular orientation along the injection direction. (c) 2005 Wiley Periodicals, Inc.