Polythiophene (PTh) nanoparticles was synthesized by cationic surfactant assisted dilute polymerization method using FeCl3 as oxidant to use as electrode material for high performances redox supercapacitors. The physical characterizations of the synthesized PTh nanoparticles were studied by FT-IR and UV-Visible spectroscopy, XRD, SEM and electrical conductivity studies. The synthesized PTh nanoparticles were used for the first time to fabricate symmetric type redox supercapacitor and its capacitor performances were studied by cyclic voltammetry, impedance spectroscopy and charge-discharge studies. The specific capacitance of the capacitor was found to be 134 Fg-1. The energy and power densities were calculated as 8 Whkg-1 and 396 Wkg-1, respectively. It was found that the PTh obtained by cationic surfactant assisted dilute polymerization method had better capacitor performances than the same obtained by the conventional chemical and electrochemical polymerization methods.