Conservative therapy, preserving bladder function, is most commonly done for the treatment of bladder tumors. However, prevention of intravesical ectopic recurrence remains to be the major postoperative problem. Between April, 1969 and March, 1986. 144 patients were treated conservatively at our Hospital. Initial recurrence occurred in 36.8% of the conservatively treated cases. Second recurrence occurred in 73.2% twice the rate of initial recurrence. No differences were noted between the recurrence rate of single and multiple tumors. Overall recurrence rate according to histological grade was 0% for Grade 0, 36.4% for Grade 1, 36.8% for Grade 2, and 50.0% for Grade 3. The overall recurrence rate of the group without postoperative prophylactic adjuvant therapy was 37.0%. The overall recurrence rate according to postoperative prophylactic adjuvant therapy was 28.6% for intravesical Mitomycin C (MMC) instillation, 30.0% for intravesical Adriamycin (ADM) instillation, 36.8% for external irradiation, 42.9% for fluorouracil (5FU) administration and 100% for 5FU + intravesical instillation. As a whole 5FU is not effective. However, in 1 patient who had had seven previous recurrences, no recurrence has occurred for over seven years after 5FU administration. Effect of adjuvant therapy differs in each case and cannot be regarded in the same light. High grade, high stage, and large (greater than 3 cm) tumors show a high recurrence rate. Progression (grade up, stage up) occurred in 11.3% of the recurrence cases.