In Stockholm county, a rapid decline in mortality from acute myocardial infarction (AMI) was observed among middle-aged men in the early 1980s. In the present study survival among AMI patients from 1976 to 1984 was investigated in order to explore whether improvements in survival may have contributed to this decline. AMI patients aged 30-74 years (n = 16,108) were identified through a hospital discharge register. Deaths within one year of hospital admission were ascertained by means of linkage to the national cause of death register. Survival 1 year after hospital admission increased in both genders during the period 1981-1984, but among women there was no uniform trend over the whole study period. The estimated age-adjusted relative risk of death within one year after hospital admission for patients with a first infarction admitted to hospital in 1983-1984 as compared to in 1981-1982 was 0.88 for men and 0.79 for women. The causes of the observed increase in survival could not be determined from this study, but changes in medical intervention as well as diagnostic improvements may have been important. Improved survival may have contributed to about 30% of the decline in mortality from AMI among middle-aged men in Stockholm county during the early 1980s.