Research has shown that family involvement in problem gambling (PG) treatment is important because families are significantly impacted and their involvement can improve treatment outcomes for the family and PG individual. This qualitative study examined facilitators and barriers to family involvement in PG treatment with a sample of PG individuals and family members (n = 11 dyads) receiving treatment at an addiction/mental health treatment centre. The study found that communication, coping skills and support facilitated family involvement; while conflict, isolation, mental health concerns and substance use were barriers to family involvement. There were three types of family involvement among participants in this study including high, moderate and low involvement. Families with high involvement described several facilitators and no barriers to family involvement. They had better treatment outcomes, as well as more positive individual and family functioning. The study demonstrates the importance and complexity of family involvement. Practice and research implications are discussed.