The article is a contribution to the discussion relating to the evolution of the relation the doctor - the patient. The Author shows the direction of changes and presents arguments, which speak for strengthening patient's rights and more and more general regard to his preferences. The point of departure is the thesis assuming the transformation of the principle salus aegroti suprema lex esto into voluntas aegroti suprema lex esto in the spirit of informed consent. Qualitative and quantitative enlarging the sources of the rights as well as growth of legal and medical awareness strengthens this tendency. The author underlines the part which is played in this case by changes in law, the development of organization uniting patients as well as the progress of knowledge in medicine. By the example of Alzheimer's disease and its characteristic symptoms can be accomplished the assessment of legal actions taken by patients. However, their effectiveness depends on circumstances in which they were undertaken.