A survey was carried out among patients who concurred to cardiologic services to know how patients preferred to be informed about their health status, and the demographic characteristics associated to these preferences, considering the following items: knowledge about the disease, information about different therapeutic options and decision-making. From 770 people surveyed, 738 (95.8%) answered the form completely. A trend to trust only in the doctor's knowledge to obtain information (81.7%), in wanting to know the options of treatment and express one's point of view (85.9%), and to involve the family in the decisions (63.2%) was observed. 9.6% preferred to receive the minimum necessary information or "to know nothing" about an alleged serious disease. Males tended less to request options and give opinion on the subject (or: 0.64), giving less freedom to family involvement (or: 1.31). people with a lower social and economical level claim fewer options (or: 0.48) and gave less family participation (or = 1.79). Natives from other South American countries had a minor tendency to demand for options and express their thoughts (or: 0.60); and the ones with lower education level trusted less in the doctor's knowledge (or: 1.81), demanded fewer options (or: 0.45) and chose not to know the severity of the disease (or: 0.56). the analysis of the demographical variables allowed to define preferences associated to age, sex, origin, education, religion and health status. In conclusion, although it is imperative to promote the patient's autonomy, individual preferences must be taken into account before informing and compromising the patient in decision-making about his disease.