We present an original method to force the horizontal growth of silicon nanowires by laser assisted chemical vapor deposition of silane. The Ar+ laser beam, tightly focused on the absorbing sample, induces a local thermal horizontal gradient over the laser spot area, which determines the growth direction of the nanowires (NWs). The reaction of formation of Si NWs occurs via the vapor-liquid-solid process, when gold particles are spread on the surface to catalyze the reaction. The effect of laser power (i.e., of laser induced local temperature) and silane pressure on the morphology of the nanowires is presented. (c) 2006 American Vacuum Society.