Nitinol alloys (Nitinol) exhibit a dramatically enhanced elasticity, known as "superelasticity", which is becoming integral to the design of a variety of new medical products. Elasticity is the most apparent of the advantages afforded by this material, but by no means the only or most important. Also discussed in this paper are features such as biocompatibility, kink resistance, constancy of stress, physiological compatibility, shape memory deployment, dynamic interference and fatigue resistance. Each of these properties is discussed and highlighted through example. Examples presented include stents, filters, retrieval baskets, and surgical tools.