The challenges in proton exchange membrane fuel cell research and development are to reduce the production cost of the fuel cell by reducing the membrane cost. This is possible by the development of an alternative membrane from a cheap source having a good prospect in fuel cell application. Sulphonation of locally available polystyrene butadiene rubber was carried out. The sulphonated polymers were characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (HNMR) to verify sulphonation and identify the site available for proton conduction. Thermogravimetric and differential scanning analyses were also conducted to investigate the thermal stability of the sulphonated polymer. An elemental analyzer was used in analyzing the percentage of sulphur in the sulphonated polymer to determine the ion exchange capacity and degree of sulphonation, while impedance spectroscopy was used to determine the proton conductivity of the synthesized membrane. Results obtained revealed that an increase in weight of polymer reduced the degree of sulphonation while an increase in sulphonation time resulted in an increase in degree of sulphonation. The synthesized membranes in their fully hydrated form were found to have conductivity in the order of 10(-3) S/cm, which increases with an increase in temperature and degree of sulphonation. Results of thermal stability further revealed that the synthesized membranes are thermally stable and can be used in high operating temperature fuel cells.