Quality has a central role in medical care. The satisfaction of the rights of people to medical care, presupposes good quality medical acts. The meaning of quality goes further than a good attention based on scientific evidence and with competent skills. It comprises patient-physician relationship where professional behavior is evaluated, based on the fundamental principles of bioethics. These principles sustain the measures to control quality of medical actions, to comply with the rights of patients to have access to a good professional care (Rev Méd Chile 2000; 128: 1385-88).