The study examined the conditions under which lay people and health professionals living in Chile find it acceptable for a physician to break confidentiality to protect the wife of a patient with a sexually transmitted disease (STD). One hundred sixty-nine lay persons, 10 physicians, 17 psychologists, and 11 paramedical professionals indicated the acceptability of breaking confidentiality in 48 scenarios. The scenarios were all possible combinations of five factors: disease severity (severe, lethal); time taken to discuss this with the patient (little time, much time); patient’s intent to inform his spouse about the disease (none, one of these days, immediately); patient’s intent to adopt protective behaviors (no intent, intent); and physician’s decision to consult an STD expert (yes, no), 2 x 2 x 3 x 2 x 2. The study also compared Chilean and French views, using data gathered previously in France. A cluster analysis conducted on the overall set of raw data revealed groups of participants that found breaking confidentiality “always acceptable” (9%), requiring “consultation with an expert” (5%), “depending on the many circumstances” (70%), and “never acceptable” (11%)”. Despite clear differences in legislation and official codes of ethics between their two countries, Chilean and French lay people did not differ much in their personal convictions regarding the circumstances in which patient confidentiality can be broken or must not be broken. By contrast, Chilean physicians, in agreement with their code of ethics, were much less supportive than French physicians of complete respect of patient confidentiality in all cases