Raman microscopy has been used to investigate the structure of as deposited and annealed polysilicon films formed by low-pressure chemical vapour deposition. The films were deposited between 620 degreesC and 570 degreesC, and the effects of various thermal annealing conditions on these samples is reported. Components of the polysilicon Raman bands have been categorised according to their wavenumber position and FWHM values. It has been shown that the degree and nature of change in material structure, is dependent upon: the starting material selected, the anneal temperature, and the anneal time.