Objective:To determine under what conditions lay people and health professionals find it acceptable for a physician to breach confidentiality to protect the wife of a patient with a sexually transmitted disease (STD).Methods:In a study in France, breaching confidentiality in 48 scenarios were accepted by 144 lay people, 10 psychologists and 7 physicians. The scenarios were all possible combinations of five factors: severity of the disease (severe, lethal); time taken to discuss this with (little time, much time); intent to inform the spouse about the disease (none, one of these days, immediately); intent to adopt protective behaviours (no intent, intent); and decision to consult an expert in STDs (yes, no), 2×2×3×2×2. The importance and interactions of each factor were determined, at the group level, by performing analyses of variance and constructing graphs.Results:The concept of breaching confidentiality to protect a wife from her husband’s STD was favoured much more by lay people and psychologists than by physicians (mean ratings 11.76, 9.28 and 2.90, respectively, on a scale of 0–22). The patient’s stated intentions to protect his wife and to inform her of the disease had the greatest impact on acceptability. A cluster analysis showed groups of lay participants who found breaching confidentiality “always acceptable” (n = 14), “depending on the many circumstances” (n = 87), requiring “consultation with an expert” (n = 30) and “never acceptable (n = 13)”.Conclusions:Most people in France are influenced by situational factors when deciding if a physician should breach confidentiality to protect the spouse of a patient infected with STD.