The 1991 Criminal Justice Act in England and Wales introduced, for those sentenced to one to four years, the concept of a sentence served half in prison and half in the community, subject to supervision and the possibility of recall. The arrangement is known as Automatic Conditional Release. This paper reports findings from a research project evaluating its first two years of operation. The paper discusses the contradictory forces and ideas which led to the introduction of the scheme and shows how they are reflected in problems of implementation; gives accounts of the reactions of prisoners and licensees; and describes practitioners' attempts to adapt traditional concepts of throughcare to the requirements of a new form of supervision. The paper concludes that compulsory post-release supervision works in the sense that licensees tend to complete it successfully and to regard it as helpful, but that it is seriously flawed in practice by lack of clarity about its purpose and difficulty in allocating appropriate resources. Tables, references