People in comorbidity with substance abuse and mental disorder is a common group in society, yet the current treatment is still insufficient in many aspects due to various matters such as the complexity of the targeted group and a lack of overall responsibility. Previous studies show that a united action of social services and access to competence development is critical for the duty of this treatment. The professionals often claimed that a meaningful relationship with the client could not be achieved because of the shortage of resources. Therefore the aim of this study has been to investigate as well as shed light on the experiences of professionals working with this type of comorbidity, regarding what opportunities and difficulties they are able to define in the work. The chosen method is a case study based on six qualitative semi-structured interviews with six professional workers from both the public sector and private sector in the south of Sweden. The results show that the experiences of the professional workers are individual but many times similar to one another. The collected empirical evidence was characterized by multiple experiences and was divided into five different themes; working method, cooperation, principalship, resources and stigma. Our findings show that the professionals participating in the study express a lot more difficulties compared to opportunities in their work. The participants experience several obstacles in all of the presented themes, such as a reluctance of responsibility, a difficulty in united action and a lack of resources to carry forward the treatment. Lastly all participants raised this issue as a matter to be handled on a government level.