In 306 subjects, 217 without and 89 with peripheral arterial disease (PAD), VIIIR:Ag and alpha 2-antiplasmin are significantly higher in PAD (p less than 0.01). In the PAD negative group the ratio alpha 2-antiplasmin/antithrombin III activity is significantly higher 1.11 +/- 0.3 in the patients with an abnormal exercise ECG typical of coronary disease than in normal subjects 1.02 +/- 0.2 (p less than 0.05). In the PAD positive group antithrombin III concentration is higher in patients with a normal exercise ECG than in patients with abnormal exercise ECG (p less than 0.05). The same is true for alpha 2-antiplasmin but not for the antithrombin III activity. Fibrinogen and VIIIR:Ag are higher in patients with a previous myocardial infarction, however, the age is also significantly different as compared to the group without previous myocardial infarction. Disturbance of the cerebral arterial circulation is characterized by an elevation of VIIR:Ag and of alpha 2-antiplasmin as compared to the values obtained in patients without this complication. There is a general tendency towards higher alpha 2-antiplasmin values with the extension of the arterial disease.