Natural fiber composites containing diglycidylphenylphosphate (DGPP) resin were prepared from DGPP, diglycidyl ether of bisphenol-A (DGEBA), and Borassus fruit fiber. Morphology, thermal, and mechanical properties of blends and fiber-reinforced composites were investigated. The tensile strength, flexural strength, and tensile modulus increased up to 10% addition of DGPP and decreased with high percentage of DGPP. The flexural strength of composites was increased up to 15% addition of DGPP due to good dispersion and toughening of DGPP in DGEBA. As observed by the SEM analysis, the matrix-fiber adhesion was poor in the case of 20% DGPP containing composites and failure occurred through fiber pullout whereas for composites with 5 and 10% of DGPP, interaction of fiber and matrix was strong and failure occurred through fiber breakage rather than fiber pullout. Addition up to 15% DGPP improved desired thermal and mechanical properties of these composites.