Poly(styrene sulfonic acid) (PSSA) was grafted onto the surface of multiwall carbon nanotubes (MWCNTs) using radical polymerization to assist the dispersion of MWCNTs before the polymerization of pyrrole. MWCNT-g-PSSA exhibited a higher dispersity in an aqueous solution compared with conventionally used carboxylated MWCNTs (c-MWCNTs), therefore, this composite acts as an excellent template for the high polymerization yield ofPolypyrrole (PPy). The measured polymerization yield was 95.5%, and its value was higher than that of PPy/c-MWCNT (61.8%). Consequently, the conductivity of the PPyIMWCNT-g-PSSA composite reached 124 S/cm, and this value was also higher than that of the PPy/c-MWCNT composite (48 S/cm) or PPylMWCNT doped with PSSA (91 S/cm). p-Toluenesulfonic acid (TSA)IHCI was selected as an additional dopant mixture to improve the electrical properties of the composite. As a result, the conductivity value of the composite improved to approximately 152 S/cm. The electrochemical and thermal stability were evaluated by cyclic voltammetry and environmental stability testing. Overall, PPy/MWCNT-g-PSSA had good electrical and mechanical properties that are desired for materials of various electric devices.