Oil palm is amajor commodity crop that contribute to Malaysian economy. Palm pressed fibres (PPF) is one of the major wastes generated during palm oil processing. Due to the large volume of waste generated each year, managing palm oil processing waste such as PPF remains as a challenging task in producing environmentally subtainable palm oil. Studies indicated that the application of microorganism can reduce the oil palm waste safely and cost effectively. This study aims to evaluate the degradation of PPF by model iron-reducing bacteria (IRB) strain, Shewanella oneidensis and three locally isolated IRB strains via microbial driven Fenton reaction. With the present of oxygen, IRB will undergo aerobic respiration to generate hydrogen peroxide, while under anaerobic growth condition with Ferric hydroxyoxides was supplied as the sole electron acceptor, IRB will reduce ferric iron to ferrous iron. Fenton reaction between hydrogen peroxide and ferrous iron generated by IRB during aerobic and anaerobic respiration respectively, produced radicals that degrade PPF. The results show that PPF degradation via Fenton reaction was greatest by S. oneidensis MR-1 compared to the three locally idolated IRB strains. Overall, this research provide promising application of microbial fenton reaction to degrade PPF waste into more simple structure for downstream processing of PPF into useful products.