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Extensive research has been carried out on the modification of polymers by direct fluorination. However, most of the work on direct fluorination is primarily limited to work on homo-polymers or in co-polymers. No information is available on the preparation of composites using fluorinated fibers or on the surface fluorination of the composites. The aim of the present investigation was to fluorinate different fibers (such as Twaron, UHMWPE fiber) using elemental fluorine and to prepare composites using different polymer matrices (HDPE, LDPE and PP). After fluorination, the adhesion properties of the fiber were improved. Grafting of MA on PP was also done as a means of introducing polar groups into the matrix. A direct fluorination chamber was designed and fabricated for this research. A series of composites based on LDPE/UHMWPE fiber, HDPE/Twaron fiber, PP/Twaron fiber were prepared. Also composites of PP/Twaron fiber using MA-g-PP as a compatibilizer were prepared. The composites were prepared using the solution method to overcome the damage to the fiber. The tensile strength and the Young’s modulus increase with increasing fiber content. The tensile strength and modulus of fluorinated fiber composites is much higher than non fluorinated fiber composites indicating that there is better mechanical interlocking between the modified fiber and the matrix. Thermal properties, obtained from DSC and DTA-TG analysis of the fluorinated fiber composites, are also improved. Contact angle measurements, as well as the calculated surface energies, indicate that the composites are more wettable and the improvement is a maximum for fluorinated fiber composites. Crystallinity is also higher for fluorinated fiber composites. The morphology, as determined by scanning electron microscopy (SEM), shows good dispersion of the fibers.