Granulomatous pneumonitis is a well-recognised complication of intravesical BCG therapy. The mechanism is sometimes thought to be 'hypersensitivity' rather than infection as in most cases mycobacteria are not cultured. Despite this it is usually treated with antituberculous chemotherapy with or without corticosteroid. We describe a case of bladder cancer treated with intravesical BCG followed by a febrile illness and malaise lasting for months and the development of miliary pulmonary shadowing, which markedly improved in around 1 year without any treatment. The clinical syndrome was less severe than some others described but this case provides evidence that, at least in some cases, no specific treatment may be necessary.