The study aims to describe and analyse how case managers reflect and act in the regards to self-determination when caring for residents with dementia diagnosis. Our main questions dealt with how the case managers handle the right to self-determination in relation to the residents’ relatives’ opinions when a person has dementia. To find answers to our questions, we interviewed seven care takers within elderly care in four different municipalitys in the Southern Sweden. We used qualitative interviews based on a semi-structured interview guide and two vignettes. The vignettes were based on two fictive narratives which both included persons with dementia but with different relatives and opinions. The purpose of the vignettes were to investigate whether there was different perceptions among the case managers in terms of consideration the residents’ self-determination in relation to their relatives. The results of the study were analyzed using Hasenfeld’s theory on Human service organizations, Lipsky’s street-level bureaucracy and Strauss’ negotiation-perspective. We displayed similarities to previous research showing that the case managers work with the residents’ best interest in mind even though relatives can be very obstinate. Our main conclusions are that the interpretation of self-determination is fluidity according to the case managers is fluidity and the case managers at some occasions try to persuade the person with dementia to apply for care and welfare. Furthermore can the relatives of the person with dementia be both beneficial and disadvantageous depending of the relation between them.