This paper analyzes the opportunities, constraints and challenges for women in Tantalum, Tungsten, Tin and Gold (3TG) supply chains in the artisanal and small-scale mining (ASM) sector of eastern Democratic Republic of the Congo (DRC). Drawing on empirical qualitative data collected during five months of field research between 2015 and 2018, the paper analyzes the governance structures of, and power relations within, 3TG ASM supply chains in the eastern DRC, with special emphasis on women's roles. The analysis offers clues as to why, in eastern DRC, women's positions in 3TG ASM supply chains changed after formalization.