Concentrations of cathepsins A, D and stefins A and B were measured in primary tumor and adjacent normal tissue of 25 patients with laryngeal carcinoma. Median concentrations of both cathepsins and that of stefin B were significantly higher in tumor tissue than in their normal counterparts (cathepsins B and D, P < 0.0001; stefin B, P = 0.01), indicating their possible involvement in the process of tumor spread. Early (T1 and T2) tumors had lower concentrations of stefins A and B than locally advanced (T3 and T4) tumors (P = 0.04). Disease-free and disease-specific survival rates at 45 months were significantly better in patients with tumor concentrations of stefins above or equal to the cut-off values (stefin A, P = 0.001 and P = 0.004; stefin B, P = 0.048 and P = 0.008), indicating that these might be of prognostic value. The concentrations of cathepsins B and D did not correlate with survival.