AbstractIn this work, chemical surface treated oil palm fibers, including alkali, maleic and silane pre‐treatments are melt blended and hot compression molded with acrylonitrile butadiene styrene into varying compositions of polymer composites. The effectiveness of the chemical pre‐treatment and fiber dispersion are analyzed with the aid of Fourier‐transform infrared spectrometry and scanning electron microscope while the influences on thermal degradation and mechanical properties of the resulting composites are analyzed through thermal gravimetric analysis and tensile test respectively. Differential thermogravimetric analysis result show that alkali, maleic and silane pre‐treatments could lower the onset thermal degradation temperature of oil palm fiber filled acrylonitrile butadiene styrene composites. The tensile test results show that chemically treated oil palm fiber filled acrylonitrile butadiene styrene composites attained enhancement in tensile strength as compared to untreated counterpart. Scanning electron microscopy observations on fracture surfaces of oil palm fiber filled acrylonitrile butadiene styrene composites found that the reinforcing efficiency of chemically treated oil palm fiber could be further increased by improving interfacial bonding between oil palm fiber and acrylonitrile butadiene styrene.