Tissue factor and tissue factor pathway inhibitor are important in extrinsic coagulation. We investigated their clinical significance in hemodialysis patients. We took blood samples, prior to initiation of routine hemodialysis, from 73 patients on hemodialysis (35 men and 38 women aged 56.1+/-11.7 years on dialysis for 82.1+/-61.0 months), and determined tissue factor and tissue factor pathway inhibitor levels by ELISA. In the patients the tissue factor level was 704.5+/-141.6 pg/ml and the tissue factor pathway inhibitor level was 44.5+/-23.3 ng/ml; both values were significantly higher than in normal controls (192.7+/-36.6 pg/ml and 18.6+/-5.7 ng/ml, respectively). In patients with shunt obstruction, tissue factor pathway inhibitor levels were significantly higher than in those without it. Therefore, the tissue factor pathway inhibitor level may be a marker of shunt obstruction.