Recently deformation-induced amorphization of TiNi shape memory alloys has been investigated extensively using cold rolling, shot peening and high pressure torsion. However amorphization of TiNi wire by cold-drawing has never been reported. In the present study, wires of Ti-50.9mol%Ni alloys were deformed severely by cold drawing. Changes in mechanical properties and microstructures were invesitgated by means of X-ray diffractometry, TEM observations (200 kV), micro-hardenss measurements and tensile tests at room temperature. X-ray diffractometry and TEM observations revealed that the severely deformed wires were composed of the mixture of amorphous and nanocrystalline B2 phase. Hardness measured on the cross-section for the as-draw amorphous/B2 TiNi were over 600Hv. The hardness value further increased by aging at 473 K for 3.6 ks. The tensile stress-strain curves had no-stress plateau, yet exhibited over 3% recoverable strain. Slope of the initial part of the tensile-stress strain curves increased with the reduction in area. The wire deformed aged at 573 K for 3.6 ks exhibited the tensile strength of 2.4 GPa, 5 % recoverable strain and apparent elastic modules of 71 GPa . Such high strength TiNi wires can be useful in medical devices.