Failure analysis investigations have shown that NiTi wire used in medical device applications can exhibit interesting fracture modes that have not been observed in other metallic materials. In particular, NiTi wires can exhibit a susceptibility to damage in local compression (“compressive damage”) associated with bending to very sharp radii, such as observed in an unresolved kink. Experiments have shown that compressive damage can lead to cracking on the compression side of a bend before cracking occurs on the tensile side of the bend. In medical device applications, compressive damage in wires has been observed in cases where failures have apparently occurred under torsional and bending loads. This paper details the fracture morphology observed with compressive damage, as well as apparent critical strains levels that cause this damage. In addition to the compressive damage-driven phenomenon, several other fracture and failure modes in NiTi wires due to tension, torsion, fatigue and corrosion are identified and characterized.