To our knowledge, no study of prevalence of migraine has ever been carried out in France. Since this is a well defined disease with precise diagnosis and therapy, it was possible for us to carry out a survey on a large population. We therefore had to build an automatic process if migraine diagnosis using simple computerized questionnaires. The results presented are these relative to a survey carried out on a working population group of about 3,000 persons. These were interviewed during the annual medical examination which workers in France have to undergo. The socio-economic consequences of migraine could thus be studied.