Successful treatment of superficial bladder cancer using nonspecific immunotherapy with Bacillus Calmette-Guerin (BCG) has been well documented. Investigation of two potential tumor-specific immunotherapeutic agents using a murine transitional-cell carcinoma model (MBT-2) is reported. The survival of mice immunized with tumor proteins obtained by treating tumor cells with either 1-butanol or ethylchlorformate was compared to the survival of animals immunized with BCG. Long-term immunity conferred by each of these agents was also assessed. Significant protection by both agents was noted in all treatment groups compared to controls. Long-term immunity was also found to result from treatment with both investigational agents as well as with BCG. Butanol-extracted antigens and ethylchlorformate polymerized tumor protein may be useful as immunotherapeutic alternatives to BCG.