The purpose of this thesis was to find out if the residents of mental health and substance abuse rehabilitation units have experienced prejudices. The hope was that the results could be used in processing the emotions related to experiencing possible prejudices in the daily life of rehabilitation units. The method to gather information was interviewing the clients of the rehabilitation centers in the area of Southern Savonia. The thesis was carried out as a qualitative research. The research material was collected by interviewing mental health and substance abuse rehabilitators in two different units. The interviewing method was a semi-structured interview. The interviews were individual interviews. The interview results were analyzed using qualitative analysis. Employees of the units were also interviewed in this thesis. The research results revealed that experiencing prejudice among rehabilitators is common: more than half of the rehabilitators interviewed had experienced prejudice. Prejudices were experienced from professional staff as well as from relatives and strangers. Most of the interviewees believed that it would be possible to reduce the prejudices against mental health and substance abuse rehabilitators. The importance of increasing awareness as a means of reducing prejudices was particularly highlighted. The rehabilitators spoke openly about how the prejudicial behavior they faced had affected their daily lives and avoiding social situations became the most common theme. It turned out that most of the rehabilitators feel like there is an open atmosphere where they can talk in the rehabilitation units. As a conclusion the study showed that change is still needed in our society to reduce prejudicial behavior towards the rehabilitation clients of mental health and substance abuse units. Prejudices have significant effects on the everyday life of rehabilitators. The widespread experience of prejudices emphasizes the need to intervene to prejudices both at the societal level and in rehabilitation units. Rehabilitation programs should include versatile forms of support to meet rehabilitators’ individual needs. The research emphasizes employees’ key role in reducing prejudices in mental health and substance abuse rehabilitation. In the future, it is important to continue working to reduce prejudices regarding mental health and substance abuse rehabilitation.