Social inequalities in coronary heart disease mortality have roots in childhood conditions, but it is unknown whether they are associated both with the incidence of the disease and the following survival. We studied how several different early-life socioeconomic factors, together with later socioeconomic attainment, were associated with myocardial infarction (MI) incidence and fatality in Finland. The data was based on a register-based sample of households from a census in 1950 that also provided information on childhood circumstances. MI hospitalizations and mortality in 1988-2010 were studied in those who were up to 14 years of age at the time of the census and resident in Finland in 1987 (n = 94,501). Parental education, occupation, household crowding, home ownership, and family type were examined together with adulthood education and income. Hazard and odds ratios with 95% confidence intervals (CI) were calculated using Cox regression (incidence and long-term fatality) and logistic regression (short-term fatality) models. Lower parental education, occupational background and greater household crowding were associated with MI incidence. In models adjusted for adulthood variables, crowding increased the risk by 16% (95% CI 5-29%) in men and 25% (95% CI 3-50%) in women. Shortterm survival was more favourable in sons of white-collar parents and daughters of owner-occupied households, but most aspects of childhood circumstances did not strongly influence long-term fatality risk. Socioeconomic attainment in adulthood accounted for a substantial part of the effects of childhood conditions, but the measured childhood factors explained little of the disparities by adulthood education and income. Moreover, income and education remained associated with MI incidence when adjusted for unobserved shared family factors in siblings. Though social and economic development in society seems to have mitigated the disease burden associated with poor childhood living conditions in Finland, low adult socioeconomic resources have remained a strong determinant of MI incidence and fatality.