The urinary CYFRA 21-1 value corrected for urinary creatinine (ng/ml/creatinine), was studied in the urine of patients with urothelial tumors. To examine its clinical significance we studied urinary CYFRA 21-1 excretion (ng/ml/creatinine), in a total of 22 urine samples from patients with bladder cancer, 7 from patients with renal pelvic and ureteral tumor, 6 from patients with urinary infection 6 from patients with urinary diversion called ileal conduit, and 8 from healthy adult men. The excretion of CYFRA 21-1 in urine was determined by two specific monoclonal antibodies (Ks 19.1 and BW 19.21). The mean value of urinary CYFRA 21-1 in healthy adult men was 1.96 +/- 1.33 (mean +/- SD) ng/ml/creatinine. Urinary CYFRA 21-1 showed a higher value in the urine of urinary infection and urinary diversion. As to bladder cancer, urinary CYFRA 21-1 showed a higher value in a larger volume of tumor than in a smaller volume of tumor in transitional cell carcinoma regardless of the grade and stage. These findings suggest that urinary CYFRA 21-1 may be a non-specific marker in urothelial tumors.