Personal powers of decision and individuality must be respected, grounded on autonomy expressed through informed consent. This paper examines data on the actual use of informed consent in public hospitals in Brazil's Federal District. A questionnaire was completed by dentists in public hospitals, and its findings show that verbal informed consent is obtained at the start of treatment in most of the hospitals. Errors were noted in the use and conceptualization of informed consent. Failing to distinguish between image rights authorization and informed consent, the documents provide little information and do not explain important aspects of the treatment. Dentists practicing in the public hospital network thus need more detailed knowledge of basic bio-ethics in order to merge the long-consolidated and regulated principle of welfare with the principle of autonomy.