We have studied the influence of electrolytes on the photovoltaic performance of mercurochrome-sensitized nanocrystalline TiO2 solar cells using LiI, LiBr, and tetraalkylammonium iodides as the electrolyte. Short-circuit photocurrent density (J(sc)) and open-circuit photovoltage (V-oc) depended strongly on the electrolyte. J(sc) of 3.42 mA cm(-2) and V-ov of 0.52 V were obtained for the LiI electrolyte and J(sc) of 2.10 mA cm(-2) and V-oc of 0.86 V were obtained for the Pr4NI electrolyte. This difference in photovoltaic performance was due to the change in the conduction band level of the TiO2 electrode. Large V-oc of 0.99V was obtained for the LiBr electrolyte due to the large energy gap between the conduction band level of TiO2 and the Br/Br-2 redox potential. Solar cell performance also depended strongly on organic solvent, suggesting that the physical properties of solvents such as Li ion conductivity and donor number affect photovoltaic performance.