Composite of coir fiber reinforced polyvinyl alcohol (PVA) was prepared by solution casting method. Tensile properties of the resulting composite materials were studied in detail. Unmodified and chemically modified coir fibers were used for the preparation of composites. Glutaraldehyde (GA) and sodium hydroxide (NaOH) solutions were introduced to modify coir fibers. Studies revealed that the PVA reinforced with modified fibers exhibited higher tensile properties. Fatty acids and waxy residues removed from the coir fiber by reacting in the presence of strong sodium hydroxide enhances the tensile strength. Glutaraldehyde crosslinks cellulose and lignin present in the coir fiber increased the strength. Therefore, a better stability is expected for their composites compared to the composites prepared from unmodified coir fibers. Formation of pits on the surface of the fibers by the removal of impurities improved the interaction between fiber and matrix. Furthermore, a comparison study was also done on the crosslinking of polyvinyl alcohol with glutaraldehyde.