We report a patient whose irritable bladder symptoms following Bacillus Calmette Guerin (BCG) instillation were satisfactorily treated by steroid administration. A 59-year-old male had undergone transurethral resection for the bladder carcinoma recurred three times. The histopathological examination revealed the tumor as transitional cell carcinoma, G1 to G2, and pTa. Subsequently an instillation of 80 mg BCG into the bladder was planned 8 times every 7 days. After the 5th instillation he presented with gross hematuria, painful micturition, pollakisuria, urgency and reduced bladder capacity of 15 ml. The dose was reduced to 40 mg and another 3 instillations were accomplished. Since conventional treatments of anti-cholinergics, analgesics and epidural anesthesia were of little help for the subjective symptoms, he was put on the steroid pulse therapy 2 weeks after completion of the BCG regimen. The treatment gradually improved the subjective symptoms and increased the bladder capacity up to 160 ml. In conclusion, we believe that the steroid pulse therapy deserves considering in the early stage of irritable bladder symptoms following BCG instillation.