Urine-Tissue Polypeptide Antigen (U-TPA) was measured in 81 patients with a previously diagnosed bladder carcinoma. U-TPA was elevated in 74% of the patients with invasive bladder cancer as compared to only 15% of the patients with superficial tumors. Only one patient without a tumor recurrence had an elevated U-TPA level (4%). The results were compared with cytological grading and flow-DNA measurements in a multivariate analysis with T-category as the result variable. U-TPA and grade showed each, independently, a significant relation (P much less than 0.001) to T-category whereas the result of the DNA measurements did not explain the variation in T-category when U-TPA and grade were already in the equation. For diagnostic purposes U-TPA seems to be of limited value but may serve as an indicator of tumor recurrence in bladder cancer patients.