The purpose of our study was to evaluate the desire of the patients on being informed about diagnosis of severe diseases, the desire to have their families informed about this situation and to participate in therapeutic decisions. 363 patients (outpatients and inpatients) of a General Internal Medicine division of a University Hospital were interviewed. The questionnaire contained specific questions on their desire to be informed of the diagnosis in case of cancer or AIDS and on their desire to have their families informed as well. Specific questions on whether they wanted to be informed of and participate of the therapeutic discussion process in case of abdominal tumors were also included. 96.1% of men and 92.6% of women showed the desire of being informed in case of cancer diagnosis and 87.7% of men and 84.2% of women wanted to have their families informed, 94.2% of men and 91% of women wanted to know the diagnosis of AIDS. While 86% of women and 76.6% of men wanted be informed in the case of a diagnosis of an abdominal tumor, only 58.5% of women and 39.6% of men wanted to give their opinion about in the case of different therapeutic alternatives. The desire to participate in therapeutic decisions was significantly lower (p<0.05) in men, people older than 60 years and inpatients. Our results showed that the great majority of the population that seeks for medical support in a Brazilian university hospital wishes to be informed on this health condition, even in case of serious illness. In addition, there are intense familiar bonds that make patients want to have their families also informed.