Environmental factors are increasingly integrated into an organisation`s procurement. The corporate purchasing function assumes a boundary-spanning role and is thus adapt to take the environmental lead. Public purchasers in particular can play an important role in the process of organisational greening which can have positive environmental effects far beyond the individual institution. Nevertheless, research in this field remains scarce. Thus, a case study was conducted in a local authority in London, involving interviews with eleven suppliers to the authority. They all showed high environmental awareness, but their ecological performance varied. Indication that the local authority contributes to greening its supply chain could be found in single cases. Environmental agreements in the contract and a partnership approach seem to be beneficial for the environmental performance in the contractual relationship. This book is directed at everybody interested in sustainable procurement, especially with a focus on the public sector. It is not only of interest for academics, but also for decision-makers in public authorities as well as in businesses.