The frequency of pulmonary embolism in patients with myocardial infarction (MI) and chronic rheumatic heart disease (RHE) has been investigated in an autopsy series. The series comprised 21530 hospital autopsies from 1960 to 1984. Altogether 5351 patients with MI and 289 patients with RHE as underlying death cause were selected for this study. Patients with RHE or old myocardial infarction (OMI) had a significantly higher frequency of pulmonary embolism than patients with acute myocardial infarction (AMI) or acute and old myocardial infarction combined (AOMI). This was true irrespective of duration of stay in the hospital during last admission. The frequency of pulmonary embolism decreased in patients with OMI or RHE from 1960 to 1984 suggestive of better therapy of chronic heart failure. A similar trend was seen in patients with AMI during a period with consistent anticoagulation treatment.