In 1985, the age-standardized (25-64) attack rate (per 100,000) for myocardial infarction, among men was 240 in the Bas-Rhin, 219 in the Haute-Garonne and 231 in the urban community of Lille and among women, respectively, 58, 28 and 51. The mortality rate for men (per 100,000) was 66 (Bas-Rhin), 57 (Haute-Garonne), 69 (Lille) and among women 18, 7 and 14. Among women, these differences are significant. A regional significant difference appears among men when cases with insufficient data are included. The sex ratio (men/women) was higher in the Haute-Garonne. 38% of death cases occurred within one hour, 76% within one day, and 89% in the first week after the first symptoms. The case fatality rate at 28 days does not differ significantly between the three registries (from 26% to 30%). The highest case fatality rates were observed in patients aged 25-34 and 55-64. The frequency of previous history of cardiovascular disease and the management of the cases were not different between regions. Diagnostic criteria problems are discussed.