Background Cardiovascular disease (CVD) is the primary cause of premature death in Western countries. Aim To assess the effect of patient ignorance of CVD risk modifiers on mortality. Methods We studied 4930 men and women in primary prevention, who consulted at the Department of Preventive Cardiology of a university hospital in France from 1995 to 2011. Questionnaires on socioeconomic level, medical history, cardiovascular risk factors, knowledge of CVD, drug intake, lifestyle and dietary recommendations, and adherence to treatments were administered by trained medical staff. Vital status (cause and date of death, in patients who died) was obtained through the French National Database. Multivariable predictive relationships with total mortality were evaluated using the Cox proportional hazards model. Results Mean follow-up was 8.6 years; 123 deaths, including 31 cardiovascular deaths, were recorded. Overall, 1305 patients (26%) were ignorant of CVD preventive measures; their mean age (53 years) was similar to that of the non-ignorant population, but most were men with a low educational level, a higher body mass index and significantly more cardiovascular risk factors (diabetes, hypertension). The ignorant group's lifestyle did not conform to cardiovascular guidelines, with less physical activity and more frequent inappropriate diet and smoking. All-cause and cardiovascular mortalities were higher among these patients. In the multivariable analysis, after adjusting for age, sex, smoking status, diabetes, hypertension, body mass index and educational status, ignorance of CVD preventive measures remained significantly associated with all-cause mortality (hazard ratio 1.93, 95% confidence interval 1.31–2.83; P < 0.01). Conclusion Ignorance of cardiovascular risk modifiers was significantly associated with all-cause mortality in a general French population. © 2016 Elsevier Masson SAS