Electrodeposition inside an insulated nanoporous template using Room Temperature Ionic Liquids (RTILs) has recently been demonstrated as a promising alternative technique for synthesizing silicon nanowires due to low cost ambient growth conditions. An improvement of the method is shown here to produce Si nanotubes. A fine adjustment of electro-chemical parameters influencing ionic diffusion inside the nanopores of the template is demonstrated to preferably lead to the growth of Si nanotubes at the expense of Si nanowires. This study shows that electrodeposition in RTILs is a competitive process to grow high surface to volume ratio nanostructures at low cost and over a large scale. It also indicates a new prospect for the technique to grow and control nanostructures such as radial core-shell nanowires.