Governments and municipalities often have lofty ambitions to reduce their environmental impact and enforce sustainability in the construction industry. With this in mind, it is important to study the ability of public clients to implement these ambitions in practice. Current research suggests that public clients have a strong potential to support change processes. One way of executing this potential is through procurement. Procurement can, and shall, according to the Swedish government, be used as a mean to reduce the environmental impact of the public sector. The purpose of the paper is to explore what implications the procurement strategies of two public clients have for their role as change agent for sustainability initiatives, within construction projects. The study was carried out by qualitative analysis of two cases, one from a Swedish municipality and one from the Swedish Transport Administration. The findings show that public clients do act as change agents at a policy level but struggles with implementing its ambitions in the project phase. Despite sustainability goals and the clients' pledged potential to act as change agents; they do not actually wish to take on all dimensions of a role as change agent. Practical implications from the findings include increased understanding for public clients of their need to engage in the change process on a management level in order to fully act as a change agent.