In this paper, we report on significantly enhanced plasticity in addition to improvement of thermal stability in Pd 40 Ni 40 Si 4 P 16 bulk metallic glass (BMG) by flux treatment. With fluxing, the plastic strain was remarkably enhanced from approximately 3% to up to 52%, which likely correlates with a larger volume of shear transformation zones. It is suggested that the flux treatment is not only a good approach to improve the thermal stability but may be a promising way to enhance the plasticity of BMGs.