We report a new strategy of nanofabrication using the focused ion beam (FIB)-based chemical vapor deposition method. It utilizes scattered Ga ions to decompose organometallic molecules of the precursor gas for depositing the metallic element on a surface with the advantage of producing uniform metallic coats on those surfaces of nanostructures which are not directly accessible to the primary beam. The method can be used to provide electrical contacts on inaccessible regions of prototype nanodevices, such as ion batteries, electrophoresis cells, cantilevers, etc, which have been demonstrated and explained by depositing Pt and W on different surfaces of 3D nanostructures.