It is projected that by 2015 there will be 133 million Americans over 45, the age at which the increased incidence of heart diseases is documented. Many will require stents. This is a multi-billion dollar industry, with over 2 million patients worldwide, 15% of whom will be equipped with stents made from Nitinol. The Food and Drug Administration, the American Heart Association, and others are calling for a new generation of stents to be manufactured from different alloys that are more flexible and more adaptable to the arteries. In this investigation, the biocompatibility of three ternary Nitinol alloys, NiTiTa, NiTiCu and NiTiCr were evaluated and compared with that of the binary alloy NiTi by exposing them to Endothelial cells under simulated physiological conditions. In an effort to assess cell proliferation and viability, two dyes, Mito Tracker Red and Hoechst, were used to highlight cell mitochondria and nucleus respectively. The cells were fixed with nature buffered formaldehyde and studied by fluorescent microscopy.