A nanoparticle TiO2 solid-state photoelectrochemical cell has been fabricated. The effect of ionic conductivity of a solid electrolyte of polyacrylonitrile (PAN)–propylene carbonate (PC)–lithium perchlorate (LiClO4) on the performance of a photoelectrochemical cell of indium tin oxide (ITO)/TiO2/PAN–PC–LiClO4/graphite has been investigated. A nanoparticle TiO2 film was deposited onto ITO-covered glass substrate by controlled hydrolysis technique. A solid electrolyte of PAN–LiClO4 with PC plasticizer prepared by solution casting technique was used as a redox couple medium. The room temperature conductivity of the electrolyte was determined by AC impedance spectroscopy technique. A graphite electrode was prepared onto a glass slide by electron beam evaporation technique. The device shows a photovoltaic effect under illumination. The short-circuit current density, J sc, and open-circuit voltage, V oc, vary with the conductivity of the electrolyte. The highest J sc of 2.82 μA cm−2 and V oc of 0.56 V were obtained at the conductivity of 4.2 × 10−4 Scm−1 and at the intensity of 100 mW cm−2.