Essential properties of Polyethylene terephthalate (PET) such as lightness, high transparency, high mechanical strength, good moisture barrier, high heat resistance, and relatively low cost make it a suitable material for the packaging of natural mineral and soft drink bottles. However, these have contributed signi cantly to household and municipal waste responsible for the growing environmental pollution that has become a threat to the planet. Low-cost, ecologically friendly treatments with the capacity to eradicate plastics, are being advocated for by scientists. This s, therefore, seeks to explore the potential capacity of Pleurotus ostreatus and Pleurotus pulmonarius in biodegrading PET plastic on two different substrates (Soil and rice straw). The substrates were contaminated with 5% and 10% plastic prior to inoculation with Pleurotus ostreatus and Pleurotus pulmonarius separately and left to incubate for 2 months. Chemical changes in the plastic were monitored using FT-IR and GC-MS. FTIR spectral analysis of PET akes displayed different shifts in the wavenumbers, changes in band intensity, and the formation of new peaks, indicating changes in functional groups. Degradation products like hydrocarbons, carboxylic acids, alcohols, esters, and ketones were detected in the GC-MS analysis of the decomposed PET plastic.