This study documents how residents experience Multiple Family Group (MFG) treatment in an 18-week residential therapeutic program for people with a severe substance disorder. Individual in-depth interviews with nine residents and three ex-residents of European descent were undertaken, and analysed using a descriptive thematic analysis. Results indicate that, prior to taking part in the program, their relationships with their families were seriously damaged and their situations often appeared complex and hopeless. After attending the MFGs all of the participants of this study experienced a number of positive changes in their relationships with their family members and partners. All interviewees said that they had gained more awareness about their interactions, better communications skills and were able to integrate these skills into their relationships with their families and partners.