Ion implantation is the standard technique for amorphizing and doping planar films and devices in the microelectronic mainstream. On the other hand, it could be successfully applied to dope axial nanostructures such as Si nanowires (NWs). We prepared high crystalline-quality Si NWs by electron beam evaporation, a well-diffused industrial technique, and we elucidated the effects of ion irradiation on these NWs. We demonstrated that ion implantation induces bending of the NW till a full alignment in the ion beam direction occurs. We find a minimum implanted fluence threshold for the deformation and we investigated the role of beam energy and of implanted fluence. These data allow us to establish a correlation between amorphization of the structure and bending of the NW.