Dual diagnosis of substance abuse and severe psychiatric illness is frequent, and the building of therapeutic relationships with this group of patients seems to be both important and difficult. An integrated treatment model has been claimed to be the preferred treatment for dual diagnosis patients. This study explores how providers in an integrated treatment model, and a substance abuse treatment model with less emphasis on psychiatric co‐morbidity, handle relationship building. Two focus groups included providers working in a Therapeutic Community (TC) and a Dual Diagnosis (DD) ward. Participants were given a short case history and asked to describe how they would approach the case. The analysis was based on a phenomenological method. All providers perceived a good relationship to be central to the treatment. Providers in the DD ward were more ready to build close relationships with the patients, and described their relationship with the patients as more crucial to treatment. The providers in the TC ascribed more importance to the role of peers and to the structure of the program itself. The providers agreed that a good therapeutic relationship is important to treatment. They differed in their opinion about how central this relationship was.