This paper discusses the implementation process of a throughcare project for short-term and remand prisoners with substance misuse problems in a local prison. The aim of the Project was to assess the needs of such prisoners and refer them on to outside agencies on release. The introduction of a new group of workers into such a highly structured environment as a prison without adequate preparation and induction and at a sensitive time, led to considerable difficulties in the short term. Despite this, the Project saw more than 1000 inmates in its first 9 months of existence�the great majority of whom were heroin users, and about half of whom had not been in contact with any drug agencies/services in the community. While the effectiveness of the Project within the prison cannot be faulted, its success in getting prisoners to contact agencies on release remains unclear. The relevance of the Project to the CARAT scheme is noted.