In many service design projects, co-design is seen as critical to success and a range of benefits are attributed to co-design. In this paper, we present an overview of benefits of co-design in service design projects, in order to help the people involved to articulate more precisely and realistically which benefits to aim for. Based on a literature review and a discussion of three service design projects, we identified three types of benefits: for the service design project; for the service’s customers or users; and for the organization(s) involved. These benefits are related to improving the creative process, the service, project management, or longer-term effects. We propose that the people involved in co-design first identify the goals of the service design project and then align their co-design activities, and the associated benefits, to these goals. The paper closes with a brief discussion on the need for developing ways to monitor and evaluate whether the intended benefits are indeed realized, and the need to assess and take into account the costs and risks of co-design.