This work seeks to investigate the nanosurface characteristics and ion release for a Ti6Al4V alloy prepared by various methods (as received and heat treated at 1300ยฐC for 2 h) with three different passivation treatments (34% nitric acid passivation, 400ยฐC heating in air, and aging in 100ยฐC deionized water). The surface and nanosurface composition are not related to the surface passivation treatments and experimental materials as evaluated by energy dispersive spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. After passivation and autoclaving treatments, the specimens were immersed in 8.0 mM ethylenediaminetetraacetic acid (EDTA) in Hank's solution and maintained at 37ยฐC for periods of time up to 16 days. The 400ยฐC treated specimens exhibit a substantial reduction in constituent release, which may be attributed to the thicker thickness and rutile structure of the surface oxides. After soaking in Hank's-EDTA solution, a significant time-related decrease in constituent release rate is observed for all kinds of specimens throughout the 0-16 day experimental period. The thicker oxides may be a factor in the improved dissolution resistance. Upon immersion, nonelemental Ca and P are both detected on the surfaces of all kinds of specimens by XPS analysis, and this could be explained by the existence of two types of hydroxyl groups (acidic and basic OH groups) on the oxide surface of the specimens.