INTRODUCTION
Bacillus Calmette-Guérin (BCG) is a live attenuated strain of Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex[1]. Since its approval by Food and Drug Administration, in 1990, intravesical BCG instillation has become a first-line adjuvant immunotherapy for the treatment of superficial urothelial carcinoma of the bladder after transurethral resection (TUR). It has shown a decrease in the recurrence rates, delay of disease progression and prolonged survival compared to TUR as monotherapy[2]. Although well tolerated without significant morbidity, BCG instillation can cause local and systemic side effects. The most serious complication is systemic infection and progressive multisystemic organ failure [3]. We report a case of culture proven BCG infection with bone marrow involvement presenting with fever and pancytopenia.