Although polyacrylonitrile (PAN) has excellent properties as a precursor of carbon fibre, octa-amic polyhedral oligomeric silsesquioxane (POSS) nanoparticles which are hybrid organicÀinorganic materials can be incorporated into PAN to tune up the properties such as the mechanical strength, thermal conductivity, and electronic conductivity for a broad range of potential applications. In this work, PAN with POSS of 1, 3, and 5 wt % based on acrylonitrile weight was prepared by solution polymerisation. The synthesised product was dissolved in dimethyl sulphoxide, followed by electrospinning. After electrospinning, the nanofibrous mats were stabilised at 250 C for 1 h. The diameter of resulting PAN/POSS nanofibrous mats were less than 1 mm, as confirmed by SEM analysis. The effect of POSS on PAN/POSS nanofibrous mats was studied by SEM, universal testing machine, contact angle measurement, Fourier transform infrared spectroscopy, wide angle X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. The usefulness of the PAN/POSS nanofibre composites was realised from the improved electrical, thermal, mechanical, and wetting properties compared to pure PAN.