Fluorophosphate-glass-fibre-reinforced poly(chlorotrifluoroethylene) (PCTFE) composites with a transmittance of 80% from 0.4 to 3.7 mu m were prepared. The transparent PCTFE composites transmit light to longer wavelengths and have a better chemical resistance to organic solvents (60-70% transmittance after immersing in p-xylene for 24 h) than transparent poly( methyl methacrylate) composites do. The tensile strength of the PCTFE increased by about 20% when it contained 1.1 vol% of unidirectional fluorophosphate glass fibre. The method for preparing the glass fibres and the composites is also described.