Firms sourcing globally have been accused of committing, supporting or just turning a blind eye to a number environmental and social problem. Based on an international survey of 680 firms' purchasing departments, this paper provides empirical evidence on global sourcing's actual contribution to social and environmental sustainability. The findings show that the level of sustainability is not directly dependent on global purchasing, but firms purchasing globally are better at making use of their purchasing proficiency and are better at fulfilling their sustainability goals.