Abstract: Possible assignments are suggested for some of the absorption bands in the 1150–400 cm−1 region of the i.r. spectra of serpentines. Polarized light was used to identify the out-of-plane vibrations in antigorites and platy lizardites and the vibrations parallel to the fibre axis in chrysotiles and fibrous lizardites. An attempt is made to correlate some known structural characteristics and the chemical composition of the serpentines with some features of the i.r. spectra.