In recent work, we reported that a hot-rolled Fe-18wt%Mn alloy exhibited high damping capacity as well as excellent mechanical properties. It was also proposed that damping capacity of the alloy was proportional to the γ/ε boundary area. In the present study, the effects of homogenization(12hrs at 1100℃) and solution treatment(1hr at 1050℃ before air cooling) on damping capacity and mechanical properties were investigated for as-cast and heat treated Fe-18wt%Mn alloy. The specimen subjected to both homogenization and solution treatment was found to show superior damping capacity and mechanical properties to the as-cast state due to removal of segregation and increase in γ/ε boundary area.