Semiconductor-sensitized solar cells (SSCs) are emerging as promising devices for achieving effi cient and low-cost solar-energy conversion. The recent progress in the development of ZnO-nanostructure-ased SSCs is reviewed here, and the key issues for their effi ciency improvement, such as enhancing light harvesting and increasing carrier generation, separation, and collection, are highlighted from aspects of surface-engineering techniques. The impact of other factors such as electrolyte and counter electrodes on the photovoltaic performance is also addressed. The current challenges and perspectives for the further advance of ZnO-ased SSCs are discussed.