Both confocal Raman microspectroscopy and atomic force microscopy (AFM) have been undertaken to study the crystalline and the morphological aspects of cast PA 6 films at a sub-microscopic scale. The percentages of the different crystalline structures present within PA 6 cast films, i.e. the monoclinic alpha, the pseudo-hexagonal beta, and the monoclinic gamma, have been measured by confocal Raman microspectroscopy. In cast films, the prevailing structure is the beta one. AFM has been used to characterize the morphology of the PA 6 films. Simultaneously, the deformed state has been considered as well. Our main interest has been to follow the evolution of the percentage of each crystalline structure as a function of the plastic deformation mechanisms which are responsible of the yielding of PA 6 films: shear banding for temperatures T lower than 160 degreesC and formation of fibrils for T > 160 'C. (C) 2004 Elsevier Ltd. All rights reserved.