Several cell biological studies have shown that the invasiveness of different malignant tumors (breast, renal, prostate, gastric, ovarian cancers) depends at least in part on the urokinase type plasminogen activator (uPA) and its inhibitor PAI1. uPA converts plasminogen into plasmin. Plasmin degrades tumor matrix components and starts invasion and metastasis. Our target was to see the possible prognostic relevance of the tumor-associated proteolytic factors and to compare with tumor size, nodal status and grading. Our results suggest that the invasive and metastatic potential of squamous cell carcinoma is correlated with overexpression of uPA and PAI1.