Thrombotic risk factors may be important in determining cardiovascular outcome in patients with symptomatic peripheral arterial disease. A cohort study with a 6-year follow-up period was established to determine the relationships between haemostatic and rheological factors and incident ischaemic heart disease (IHD) and stroke events in patients with peripheral arterial disease. A consecutive series of 607 patients with intermittent claudication was examined between 1989 and 1990 at the Peripheral Vascular Clinic, Royal Infirmary of Edinburgh. Main outcome measures were combined fatal and non-fatal stroke, non-fatal myocardial infarction (MI), coronary death and total coronary events. A total of 210 patients died during follow-up. 203 patients did not experience a vascular event or deterioration of limb ischaemia. Median levels of fibrinogen, von Willebrand factor (VWF), tissue plasminogen activator (t-PA) antigen, fibrin D-dimer and whole blood viscosity were significantly higher in those who experienced an event compared with those who did not. After adjusting for age and sex, fibrin D-dimer was significantly associated with risk of non-fatal myocardial infarction (RR 1.50, 95% CI 1.09-2.06, P < or = 0.01). Both fibrinogen and fibrin D-dimer were associated with risk of total coronary events (P < or = 0.05). The risk of stroke was related to baseline levels of t-PA antigen (RR 1.87, 95% CI 1.04-3.34, P < or = 0.05) and whole blood viscosity (RR 1.33, 95% CI 1.07-1.65, P < or = 0.01). All the relationships became weaker and statistically non-significant after further adjustment for cigarette smoking, systolic blood pressure, glucose and baseline IHD. The associations of these factors to IHD and stroke may therefore be partly related to cardiovascular risk factors, but are likely to be important in the pathogenesis of future atherothrombotic events in subjects with peripheral arterial disease.