Plates for long bone fractures are a major element of internal fixation technique includes various important developments in designs, materials, and implementation process during the last century. The main purpose of this paper was to introduce a new series of green composites as a plate for bone fracture applications. These green composites offer many advantages over traditional composites and biocomposites based on synthetic polymers. In current work, the new green composites bone plate based on two types of biopolymers involves biopolymethylmethacrylate thermoplastic material and bioepoxy thermosetting material reinforced with randomly oriented coir natural fiber at different weight fractions (5, 10, 15, and 20%) were fabricated by hand lay–up technique. Four forms of green composites; alkali treated with 1% NaOH and untreated coir biopolymethylmethacrylate groups A and B respectively, alkali treated with 1% NaOH and untreated corn bioepoxy groups C and D respectively were investigated. The mechanical properties were tested (tensile, and compact tension) under a flow of phosphate buffered saline PBS at 37 ◦ C has been reported. The experimental results showed that the chemical treated coir green composites group A have the best mechanical properties than other groups under PBS condition while the untreated coir green composites group D have the weak mechanical properties due to plastization by soaked in PBS solution.