The aim of this study was to compare fibrinolytic parameters in two subgroups of young survivors of myocardial infarction: group A (n= 14) with silent myocardial ischaemia and group B (n= 15) without silent myocardial ischaemia, as assessed by 24 h Holter electrocardiogram monitoring. Only men aged 33–46 years who were in a stable condition at least 6 months after the acute event were included in the survey. All patients were normolipaemic or had only mild hyperlipidaemia, non-diabetic, normotensive, noncurrent smokers and with a normal body mass index. The control group consisted of 15 age-matched healthy men. Blood samples were taken at 7.30 a.m. In the group A patients, we found higher mean levels of tissue plasminogen activator (t-PA) total antigen (11.1 versus 6.9 ng/ml,P< 0.01), its inhibitor plasminogen activator inhibitor-1 (PAI-1) antigen (58.1 versus 34.8 ng/ml,P< 0.01), PAI-1 activity (4.9 versus 3.4 U/ml,P< 0.05) and tPA-PAI-1 complexes (5.1 versus 3.5 ng/ml,P< 0.05) as well as a lower level of t-PA activity (0.5 versus 0.8 IU/ml,P< 0.01) and free t-PA antigen (0.8 versus 1.3 ng/ml,P< 0.01) compared with the controls. However, group A patients exhibited higher PAI-1 antigen levels (58.1 versus 41.6 ng/ml,P< 0.05) than those without silent ischaemia. There were no differences between group B and controls in any of the parameters measured. Our results indicate that patients with more severe disease, as revealed by silent myocardial ischaemia, had lower levels of free t-PA as a result of the excess of PAI-1.