An evaluation of a two-year project that aimed to move the practice of two specialist substance misuse treatment teams towards greater involvement of family members. Success was evaluated using a combination of: detailed process notes of all project meetings and events, collection of practice case examples, an inventory of new team procedures, individual interviews with team members, end of project focus groups, a final auditing of the involvement of family members, and completion of the attitudes to addiction-related family problems questionnaire (AAFPQ) before and after the project. Audit and AAFPQ data were also obtained from comparison teams. The conclusion is drawn that the project was successful in changing team practice in the desired direction: by the end of the project both teams were capable of acting as demonstration sites for family-oriented alcohol and drug problems treatment. The paper includes details of the family work conducted and its perceived benefits. Also discussed are the initial barriers to family involvement, a number of issues that remained unresolved, and the question of whether such changes are sustainable.