The probation service has always been closely associated with the criminal courts, but in recent decades it has also been encouraged to work more closely with a range of public and voluntary sector agencies. This chapter examines probation’s changing relationships with the courts, the police and the prison service. We begin by exploring the changing relationship with the courts, arguing that probation workers no longer view themselves as merely ‘servants of the court’. We follow this with a discussion of the concept of ‘partnership’ and the ways in which criminal justice agencies’ interactions have been conceptualized in policy and legislative changes. We then analyse probation-prison and probation-police relationships pre-and post-1998 and, drawing on Davidson’s (1976) typology of inter-organizational relationships, argue that, despite both structural and cultural transformations, there remain cultural continuities in each organization that create tensions, the significance of which (both positive and negative) should not be underestimated. While recognizing that the probation service works with numerous other organizations in the community, our research found that it has been the changing nature of relationships with these three key agencies that has most greatly affected the occupational cultures of probation workers.