The acoustic birefringence method has been used since a long time for metallic materials to detect residual stresses. This method is rarely used for polymers and composites due to the strong attenuation of the acoustic signal. Moreover, for thermoplastic polymer, with a slight anisotropy (known as texture for metals), coupling with applied stresses, extends the complexity of the residual stresses determination. The slight anisotropy of thermoplastic polymer should be studied with shear waves prior to the residual stress determination. If the material is perfectly isotropic, we are able to detect and quantify the residual stresses. If the material is slightly anisotropic, it is also possible to evaluate residual stresses by taking into account the directions of the principal axes of material anisotropy. (C) 2015 Society of Plastics Engineers