Urine oncofetal fibronectin (OnfFN) has proven useful in the assessment of malignant diseases such as transitional cell carcinoma (TCC) of the bladder. This study aimed to explore whether OnfFN may identify benign and common urinary diseases. Methods. The urine OnfFN concentrations from patients who had bladder TCC (8 patients), benign urinary diseases (10 benign prostatic enlargement [BPE] patients, 10 urolithiasis patients), or controls (10 healthy individuals) were determined by ELISA and compared. Results. The urine OnfFN concentration was significantly higher in patients with bladder TCC and lithiasis (mean±SE 0.43±0.18 and 0.45±0.23 ug/mL) than in patients with BPE and in healthy individuals (0.15±0.06 and 0.10±0.02 ug/mL, p<0.05). The urine OnfFN level (cutoff value 0.038 μg/mL), was able to identify 75% of patients with bladder TCC, 60% of patients with BPE and 80% of patients with urolithiasis, achieving a sensitivity of 0.75 for the recognition of either cancer or a urinary disorder. The OnfFN level had a high sensitivity (0.9) for the identification of urolithiasis. Conclusion. The urine OnfFN level proved helpful in the identification of bladder TCC patients. However, it had a better performance for the identification of urolithiasis, highlighting the potential usefulness of OnfFN as a biomarker for urothelial inflammation and repair.