Mesoporous TiO2 nanospheres that were co-doped with Zn and Sr were synthesized via a simple hydrothermal method. These materials were used as the photoanode in dye-sensitized solar cells (DSSCs). Field-emission electron microscopy showed that the nanospheres were monodisperse and interconnected, while transmission electron microscopy (TEM) showed that the nanospheres were composed of different nanostructures (nanotubes, diamond and sheet-like structures). Scanning TEM showed a homogeneous distribution of Sr, Ti, Zn and O throughout the nanospheres. When the Zn, Sr co-doped mesoporous TiO2 nanospheres were incorporated into DSSCs, a device efficiency of 4.6%, a short circuit photocurrent density of 8.63 mA cm(-2) and an open circuit voltage 0.72 V were achieved. The efficiencies of these devices were higher than that of a comparison device (2.9%) that contained TiO2 (P25).