Bacillus Calmette-Guérin (BCG), a live attenuated strain of Mycobacterium bovis was first described as a vaccine against tuberculosis in 1921. The use of intravesical BCG to treat non-muscle invasive bladder cancer (NMIBC) was first described by Morales in 1921. The therapeutic effect of BCG is related to stimulation of the immune system following direct contact with tumour cells. As a result of this intended immune response some minor symptoms including fever, malaise and bladder irritation manifesting as dysuria, urinary frequency and mild haematuria, are expected. These side effects are however, generally easily managed and well tolerated. Severe complications are rare and can be temporally remote from the instillation of therapy. In this report we describe the case of a 74-year-old immunocompetent man with biopsy confirmed BCG T11/12 discitis and adjacent osteomyelitis of the T11/T12 vertebral bodies with an associated an epidural abscess following intravesical administration of BCG therapy for recurrent bladder transitional cell carcinoma (TCC).