AbstractAlthough the importance of green supplier integration has been recognized, our knowledge on what influences green supplier integration remains limited. Based on transaction cost theory and social exchange theory, this article develops hypotheses regarding the impacts of supplier trust and relationship commitment on green supplier integration, and the moderating effect of monitoring difficulty. We conduct hierarchical regression analyses to test these hypothesized relationships using survey data collected from 187 Chinese firms. The results reveal that supplier trust is positively related to normative commitment and instrumental commitment. Furthermore, normative commitment and instrumental commitment are positively related to green supplier integration, and partially mediate the relationship between supplier trust and green supplier integration. The results also indicate that monitoring difficulty negatively moderates the relationship between supplier trust and instrumental commitment, but does not significantly moderate the relationship between supplier trust and normative commitment. This study contributes to theory and practice by opening the “black box” of the trust–integration link.