Laser Raman spectroscopy (LRS) has been employed to characterize the structure and morphology of a series of carbon fibres, to assess the combined effects of ultimate firing temperature (UFT) and pre-graphitization drawing during manufacture and, finally, to investigate the influence of oxidative treatment upon the integrity of the fibre surface. Ten types of PAN-based carbon fibres of varying modulus, diameter and manufacturing method, were examined. All their spectral features were recorded and analysed in terms of position, bandwidth and band intensity. Low-modulus fibres, produced at low graphitization temperatures, exhibit weak and broad Raman bands in the 1200-1700 cm(-1) frequency region. With the increase of the firing temperature, the spectral features sharpen and new lines appear at higher frequencies. The observed changes in the Raman spectra are discussed in detail and related to alterations in the conditions of manufacture.