Although Sustainable Public Procurement (SPP) is often seen as a powerful tool to drive sustainability across its supply chain, there is little available research in terms of how SPP actually influences its suppliers’ sustainability practices and what challenges are being faced during the process. In this study, we shed light on both issues by exploring SPP using Institutional and Power Dependence Theory in the context of the surgical instrument industry in Sweden. Methodologically, the study is grounded in an exploratory design and employs in-depth interviews with multiple stakeholders to gain a holistic understanding of the phenomena being studied. The study revealed that SPP mainly influences suppliers by requiring them to evaluate their own sustainability practices, engage in collaborative actions and make alterations when they fail to comply with the contractual terms.The most significant challenge resulted to be the lack of resources, resulting in the inability to perform sufficient follow-ups, engage in meaningful conversations with suppliers and procurers having to buy unsustainable products because of their tight budgets. Another major challenge was Sweden’s forerunner position when it comes to SPP on an international level, resulting in reluctancy on the part of international suppliers to alter their sustainability practices.