Plasma fibrinopeptide A (FPA), fibrinopeptide B β 15-42 (FPB β 15-42), and fibrin/fibrinogen degradation products (FDP) were measured before treatment for the determination of the diagnostic value of coagulation and fibrinolytic molecular markers in patients with pulmonary thromboembolism (n=16) and myocardial infarction (n=8). The levels of all markers measured prior to treatment were significantly higher in patients with pulmonaly thromboembolism than those in the patients with acute myocardial infarction, irrespective of shock (FPA, 40.0±22.1vs. 17.9±24.8ng·ml-1, p=0.0085; FBP β 15-42, 34.1±20.8vs. 12.8±8.7ng·ml-1, p=0.0044; FDP, 37.5±36.7vs. 6.3±6.5μg·ml-1, p=0.0022). All of the markers had high sensitivity, specificity and predictive values for the diagnosis of pulmonary thromboembolism when the cut off points of FPA, FPB β 15-42 and FDP were set at 20ng·ml-1, 15ng·ml-1 and 10μg·ml-1, respectively. We concluded that: 1) the markers measured in this study are all useful for the differential diagnosis of pulmonaly thromboembolism and acute myocardial infarction, and 2) pulmonaly thromboembolism is the most likely diagnosis when any of the following is positive: FPA>20ng·ml-1, FPB β 15-42>15ng·ml-1 or FDP>10μg·ml-1.