Major complications following installation of bacillus Calmette Guérin (BCG) in the bladder as treatment for early stage cancer are rare and there are only few reports of BCG isolated from patients with suspected "BCGitis". We report a case where sputum culture yielded a BCG strain identical to one used two years earlier to treat the patient's bladder cancer. Some aspects were challenging in differential diagnosis: the patient's prior history of pulmonary tuberculosis ten years earlier and a two-year interval since BCG installation. PCR analysis and culture finally provided the diagnosis disseminated BCG infection.