Global purchasing and offshoring are established strategic means for lowering costs and improving competitiveness. However, firms purchasing globally have also been accused of committing, supporting or just turning a blind eye to a number of environmental and social misdemeanours, such as disregard for environmental regulation, poor working conditions and corruption. The purpose of this paper is to provide quantitative evidence, based on a large scale survey, on how global purchasing actually impacts sustainability performance. The paper finds that there are no significant differences in sustainability performance between firms purchasing globally and firms purchasing regionally. However, firms purchasing globally are significantly more likely to fulfil their sustainability goals compared to firms purchasing regionally. Moreover, only firms that purchase globally show a significant impact of sustainability programmes on supplier sustainability compliance. Global purchasing can thus aid in social and environmental responsibility if it is accompanied by ambitious sustainability targets and sustainability programmes.