The present article reports the synthesis of nanocomposites of polypyrrole along with non-precious metal chalcogenide, cobalt-disulfide. A simple sonoelectrochemical method was carried out in order to fabricate novel composite electrode materials composing polypyrrole, CoS2 and decorated Pt nanoparticles on multi walled carbon nanotubes, MWCNTs. Studying on electrocatalytic activity revealed that the presence of CoS2 nanoparticles along with MWCNTs and Pt nanoparticles played a prominent role in enhancement of proton reduction to hydrogen gas. The possible mechanism of electrocatalytic activity by nanocomposite films is also discussed. The PPy(CoS2)MWCNTsPt nanocomposite film exhibits extremely low overpotential (0.03 V vs. RHE), and high current density for HER in acidic solution. The activity enhancement can be attributed to the large active electrochemical surface area of MWCNTs and also porous structure of PPy provides excellent attachment of CoS2 and Pt nanostructures to the matrix. In addition, the HER is further improved due to stronger adsorption of hydrogen to the disulfide anions in CoS2 structures. (C) 2016 Elsevier B.V. All rights reserved.