The concept of the contract has been invoked with increasing frequency in the literature on social work practice in recent years. Since the process of negotiation that is present in all relationships takes many different forms, the idea of contracts is complex, and can be confusing. This paper outlines the different meanings associated with the term, and suggests that a complete understanding of contracts requires a developmental perspective. Further, contracting needs to be seen as an ongoing transaction as well as a series of static agreements.