Biomedical devices are finding increasing use in biliary applications. This study examined the electrochemical behavior of nitinol in two simulated bile solutions. Tests were performed on mechanically polished and electropolished nitinol wire using cyclic potentiodynamic polarization and electrochemical impedance spectroscopy. The impedance data were analyzed using equivalent circuit models to evaluate the capacitive and resistive components of the surface oxide at different potentials. The cyclic polarization results together with the impedance data were used to characterize changes in the electrochemical behavior in each bile solution and to determine whether nitinol exhibited a difference in behavior between the two bile solutions. In addition, the cyclic polarization results were compared with those obtained in phosphate-buffered saline.