The role of fibrinogen and other haemostatic factors in prediction of peripheral arterial disease (PAD) has not been established. We examined the associations of plasma fibrinogen, von Willebrand Factor (vWF), tissue plasminogen activator (t-PA) antigen, fibrin D-dimer, and factor VII with the development and clinical progression of PAD. In the Edinburgh Artery Study, 1592 men and women, aged between 55 and 74 years, were followed prospectively over 5 years to detect the onset of PAD, and the deterioration of established PAD. At baseline, 418 individuals had evidence of PAD and 60 (14.4%) subsequently deteriorated. 1080 subjects had no baseline disease, but 59 (5.5%) developed PAD during follow-up. Median levels of fibrinogen and vWF were higher in the group developing disease compared with the group which did not (2.78 g/l versus 2.57 g/l, P< or =0.01; 116 IU/dl versus 104 IU/dl, P< or =0.05; respectively). After adjusting for age and sex, fibrinogen (P< or =0.01) and vWF (P< or =0.05) were significantly associated with the risk of developing PAD. The association between fibrinogen and development of disease remained after adjusting for cardiovascular risk factors and baseline ischaemic heart disease (relative risk, 1.35, 95% confidence interval, 1.05, 1.73; P< or =0.05). None of the haemostatic factors were significantly associated with progression of PAD. In conclusion, plasma fibrinogen levels are related to the future onset of PAD, providing further evidence of a possible role of elevated fibrinogen in the development of atherosclerotic disease.