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In this study 32 patients whom had only one superficial bladder tumor (T?-T1 stage) were selected to investigate the effectiveness of either BCG of Alfa-Interferon in preventing the recurrence of tumor. The other aim of this study was to compare the ideal regiment for the patient. These patients previously had neither tumor nor immunotherapy. The patients were divided randomly into two groups, each consisting of 16 people, and they were given the chosen medicine two weeks after surgery of tumor, which is usually superficial tumor (TCC type). 10 million unit of Alfa-Interferon in amount of 7 dose was injected weekly in those patients in group 1 and 120 mg BCG in group 2 respectively. Tumor recurrence in those patients, which receive interferon, was 50% and those that receive BCG was 18.5% respectively (P=0.07). The average recurrence of tumor in group 1 was 0.046 for one person per month (Patient/month) and the same index for group 2 was 0.015 recurrence for each person per month. Relative risk in equal to 3 (Relative risk=3) with accuracy of 95% between (0.87-10.38) but in those patients that were under ?-Interferon treatment only 4, and in BCG group 13 patients got the side effects of medicines.