Background: BCG is a safe and effective live attenuated vaccine for prevention of serious tuberculosis. The infant below 1 month receive BCG vaccination in many country vaccination schedule. However, some patients with immunodeficiency were suffered from BCGosis due to live attenuated vaccine. We present a case of BCGosis in severe combined immunodeficiency (SICD) after unrelated hematopoietic stem cell trasnplantation (HSCT). Case: An Arab Emirate 3 month-old girl was transferred to our division due to fever and generalized lymphadenopathy. In family history, her elder brother died because of immunodeficiency. She received BCG about 1 month of age, and got frequent pneumonia and skin rash. She was diagnosed with SCID, and transferred to our hospital for HSCT. We identified new DCLRE1C gene mutation for autosomal recessive SCID. She was transplanted with FMM-PBSCT. She was stable until post-HSCT 3 months. We performed lymph nodes biopsy because of fever with generalized lymphadenopathy. The pathologic findings showed tuberculous granuloma and positivie AFB. We evaluated abdominal CT, which was showed nearly intestinal obsruction due to generalized mesenteric lymph nodes enlargement. We started four anti-tuberculosis (TB) medication. She was improved in clinical manifestations and radiologic findings at about 9 month of anti-TB medication. She was followed up with good condition in out-patient clinic and received with anti-TB medication. We have to consider early live-attenuated vaccination in family history with immunodeficiency, and neonatal screening test for immunodeficiency.