As a result of damage associated with recent earthquakes, new technologies to reduce the response of buildings and other infrastructure have been sought.  This study looks at the use of NiTi superelastic shape memory alloys (SMAs) as the basis for a new class of devices for mitigation of earthquake loads.  SMA bars of the same composition but varying sizes are tested under cyclic loadings at both strain levels and loading rates consistent with seismic events.  The effect of bar size and loading history on the strength, damping capacity, and recentering capability is evaluated.  The results show nearly ideal superelastic behavior at loading levels and rates typical of an earthquake for all sizes of specimens.  The recentering capability existed even for the largest specimens.  Equivalent viscous damping values are shown to be low, less than 7%, even at large strain levels.  However, the combination of both recentering and small amounts of supplemental damping suggest the ability of incorporating superelastic SMAs in building systems for seismic response reduction.