The diagnosis of dementia means the loss of control over their lives of many patients. Slowly, they are getting lost of their cognitive abilities including their linguistic skills. People with dementia possess in the course of the disease, lesser criteria of a good life or less in fulfilling social expectations. However, the dignity of the patients with dementia does not depend on their medical condition, neither autonomy nor self-determination. Their dignity comes to human dignity just like everyone, despite of getting old with this disease with a certain amount of self-esteem being diminished. Their self-determination has not completely vanished but it will be limited and in a paradigm that is increasingly more confined. The knowledge of the dementia disease is a good training to nursing staff and the elaboration on the biography of patients suffering under this disease are essential ways to be a professional nurse, in order to preserve patients’ dignity and enhance their self-confidence in the course of the their ailment. Biography work provides a better opportunity for a professional health and nursing care, an access to the patients and to build an appreciative relationship with them.