The bending and thermic behaviour of raw banana, pineapple leaves and S-glass poly-lactic acid (PLA) composites was examined in this study. In order to achieve improved thermo stability, raw banana and pineapple leaf fibres were hybridised using S-glass fibre. The bio-composites had 25, 35 and 45 wt percent of fibre in the shape of long fibres about 30 cm long, with various fibre ratios in the composite samples. The composites were produced by the manufacturing method of the hot press. The goal of this work was to examine the effect of different fibres, using bending tests and dynamical thermal stability tests, on the thermal properties of bananas/pineapple leaf/S-glass fibre/PLA. The effect on the bending and dynamic thermal stability of banana/pineapple leaf/S-glass/PLA hybrid composite hybridity was analysed for various hybrid fibre ratios and the hybrid composite PLFS 25 demonstrated the greatest bending strength and flexural modulation in all composite samples. The banana/pineapple leaf/S-glass fiber/PLA hybrid compounds have dynamic thermal characteristics that vary with their fibres, probably because of difference in the chemical composition of the three fibres. The PLFS 25 hybrid composites showed the maximum thermal dynamic characteristics to their optimal hybridisation of both fibres. The analysis of thermal dynamic properties demonstrated that the dynamic thermal stability of PLA composites had little impact on both the pineapple leaf/S-glass fibre and banana/s-glass fibre. © 2023 Elsevier B.V., All rights reserved.