Abstract. In this study, the effect of polymeric Methylene Diphenyl Diisocyanate (pMDI) chemical treatment on kenaf (Hibiscus cannabinus) reinforced thermoplastic polyurethane (TPU/KF) was examined using two different procedures. The first consisted of treating the fibers with 4%pMDI, and the second involved 2%NaOH + 4%pMDI. The composites were characterized according to their tensile properties, Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The treatment of the composite with 4%pMDI did not significantly affect its tensile properties, but the treatment with 2%NaOH + 4%pMDI significantly increased the tensile properties of the composite (i.e., 30 and 42% increases in the tensile strength and modulus, respectively). FTIR also showed that treatment with 2%NaOH + 4%pMDI led to the strongest H-bonding. Additionally, the surface morphology of specimens after tensile fracture confirmed that the composite treated with 2%NaOH + 4%pMDI had the best adhesion and wettability