Adverse reactions induced by BCG vaccination are rare and appear either in the form of lymphadenitis or osteitis. One of the rarest complications of the vaccine is disseminated mycobacterial infection which mostly occurs in infants with immune deficiency. In this paper a case of disseminated BCG infection is reported in a four-month-old infant suffering from severe combined immunodeficiency (SCID). Plain radiographs showed multiple osteolytic lesions in skull and extremities abdominal sonography revealed multiple nodules in the liver and spleen in thoracic radiography disseminated interstitial infiltration was observed, and gastric tub age culture tested positive for Mycobacterium bovis.