Elevated levels of soluble uPAR (s-uPAR) and other fibrinolytic parameters functionally related to the urokinase-type plasminogen activator system might indicate the presence of cancer cells. In 25 breast cancer patients with metastases s-uPAR was significantly increased compared with 25 patients without metastases and with 25 healthy controls: 420 pg mL-1 vs. 145 pg mL-1 (P = 0.005) and 190 pg mL-1 (P = 0.003). Plasmin-alpha2-antiplasmin (PAP) complexes and d-dimers were significantly increased in breast cancer patients with metastases compared with patients without metastases and with healthy controls. The levels of plasminogen activator inhibitor (PAI)-1 activity, uPA antigen and factor (F)XIIa did not significantly differ between the patient groups and healthy controls. PAP complexes (529 microg L-1 vs. 420 microg L-1; P = 0.03), d-dimers (278.5 ng mL-1 vs. 79.0 ng mL-1; P = 0.005) and FXIIa (1.64 ng mL-1 vs. 1.19 ng mL-1; P = 0.01) were significantly higher in patients with metastases not surviving compared with patients with metastases surviving the 3-year follow-up period. Plasma s-uPAR levels in the patients with metastases did not discriminate between patients surviving and patients not surviving after 3-year follow-up. No significant differences in s-uPAR or any of the other parameters were found in the five patients developing metastases during follow-up. A single value of s-uPAR is of limited value in the follow-up of breast cancer patients with and without metastatic disease and does not predict survival or future metastases.