The 5-Step Method has now been evaluated in a number of studies in the United Kingdom and Italy. This chapter will present the evidence which summarizes how the intervention can help family members. The evidence is organized into two sections. First, quantitative evidence from feasibility and controlled studies in primary care, specialist services and community settings is summarized and discussed. Second, qualitative case study material is used to illustrate how the 5-Step Method can benefit family members. Finally, the chapter will draw together the conclusions which can be derived from the library of evidence which has been collected. It is concluded that when all strands of evidence are considered together, the 5-Step Method emerges as a very promising approach to reduce addiction family-related harm. The evaluation studies conducted to date provide a strong platform from which to roll-out the 5-Step Method in routine practice.