The influences of different fibre extraction methods and chemical treatment on the structural textures, thermal degradation patterns and tensile properties of Entada mannii (Olive Tisserant) plant stem fibres were investigated. The fibres were extracted manually from the plant stem using two conventional methods, hand stripping (HS) and hand beating (HB). After drying, the fibres were either left untreated or were treated with potassium hydroxide (KOH) and then characterised using chemical analysis, scanning electron microscopy (SEM), thermogravimetry analysis and tensile analysis. The results showed that chemical treatment with KOH enhances the removal of lignins and hemicelluloses in the fibres. The KOH treated fibres were also more thermally stable when compared with untreated fibres. SEM analysis revealed exposed surfaces composed of a continuous network of micro fibrils for the KOH treated fibres. In contrast, the untreated fibres had smooth surfaces, suggesting the sub-cell structure is covered by lignins and hemicelluloses. The tensile property results demonstrated a significant improvement in tensile strengths, elastic moduli, and resiliencies for the chemically treated fibres. It was also noted that the best combination of tensile and thermal properties was achieved with the hand stripped, KOH treated fibres.