Ultrathin and uniform Bi(2)WO(6) square nanoplates of ∼9.5 nm thickness corresponding to six repeating cell units were prepared in the presence of oleylamine using a hydrothermal route. The Bi(2)WO(6) nanoplates show great potential in the utilization of visible light energy to the highly efficient reduction of CO(2) into a renewable hydrocarbon fuel. On the one hand, the ultrathin geometry of the nanoplates promotes charge carriers to move rapidly from the interior to the surface to participate in the photoreduction reaction. This should also favor the improved separation of photogenerated electron and hole and a lower electron-hole recombination rate; on the other hand, the Bi(2)WO(6) square nanoplate is proven to provide the well-defined {001} facet for two dominantly exposed surfaces, which is a prerequisite for the high level of photocatalytic activity of CO(2) fixation.