Manitoba's hospital separations and physician medical files were linked for the fiscal years 1984-85 and 1985-86. The result was a study file consisting of records for 5,293 males and 3,143 females, who, during this period, suffered an Acute Myocardial Infarction (AMI), commonly called a heart attack. Merging the two types of files created a comprehensive data base for these AMI victims. The Manitoba age-sex standardized AMI rate was 38.0 per 10,000 population. Age-specific rates were higher for males than for females for all age groups. Hospitalized cases accounted for 7,201 individuals or 85.4% of AMI victims. Age-sex standardized rates of hospitalization per 10,000 population ranged from 27.1 in the Central region to 36.0 in the Westman region. The Manitoba age-specific rates of hospitalization for males in the 35-54 and 55-64 age groups were about three times the female rates for the same age groups. One quarter of AMI hospitalized victims died in hospital. The Manitoba age-specific death rates for males in the 35-54, 55-64 and 65-74 age groups were double the rates for females in the same age groups. Of the 8,436 AMI victims under study, 86.4% had at least one other concurrent medical condition such as angina, other forms of ischemic heart disease, diabetes, or hypertension. Of AMI victims, 93.8% underwent at least one of the following procedures: coronary artery bypass surgery, angiogram, electrocardiogram, cardiac catheterization, arteriography, or blood cholesterol testing. A higher percentage of procedures was performed on males than on females.