A counter electrode of dye-sensitized solar cells (DSC) is an important component, which often limits the cell performance. Here we report a low-cost and high-performance polymer counter electrode of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) containing TiO2 nano-particles for dye-sensitized solar cells. Catalytic characteristics of the counter electrode are significantly improved by adding TiO2 nano-particles to PEDOT:PSS. This improvement is attributed to catalytic activation due to an increase in the surface area of the counter electrode and an increase in conductivity of PEDOT:PSS due to its structural change. A dye-sensitized solar cell using the polymer counter electrode shows 8.27% of efficiency and 16.39 mA cm(-2) of short circuit current density, higher than 7.59% of efficiency and 14.75 mA cm(-2) of short circuit current density of a cell with the conventional Pt counter electrode. (C) 2015 Elsevier B.V. All rights reserved.