Based on a detailed study of the fundamental vibrations in the mid-IR (MIR) region and supported by NH/ND-deuteration expts., variable-temp. and polarization measurements, the assignment of overtone and combination bands in the near IR (NIR) spectrum of polyamide 11 (PA11),[-(CH2)10-CO-NH-]n, is presented. The results can be readily transferred to the spectral interpretation of homologous aliph. polyamides thereby providing an improved understanding of the NIR spectra of this class of tech. important polymers.