This study addresses to critical issues related to the role of anxiety in myocardial infarct. Is the predictive value of the Anxiety Scale Questionnaire (ASQ) to be found in content of items and its self-rating by the subject or in response style to the questionnaire? Would anxiety play in certain circumstances a positive role in that it drives the individual to seek early medical treatment? Differences in anxiety scores, response style indices and factorial structures of the ASQ items reveal : 1. myocardial infarction subjects have higher, but not significantly higher, anxiety scores relative to healthy volunteers to an atherosclerosis screening test and healthy control individuals matched for age, sex and socio-economic status, 2. healthy volunteers are characterized by extreme response style that could reveal their involvement in the testing situation; 3. control individuals show a tendency to intermediate response; 4. the lack of invariance of factorial structure across the three groups suggests that each of them has a specific organization of anxiety. Scale-checking style, though strongly associated with the content of items, could have a predictive value since, anxiety levels being equal, subjects may be differently involved in their answers. The assumption is supported by the specific organization of anxiety evidenced in each group considered. A relation between such organization and preventive behaviour is not infirmed by the present data and ought to be further analyzed.