Bronchiolitis obliterans organising peumonia BOO) is an uncommon inflammatory lung condition involving the terminal bronchioles and alveoli, which is responsive to treatment with corticosteroids. Patients usually present with dyspnoea, cough and fever. Two cases are described here; both had haemoptysis and were initially treated as community acquired pneumonia. Diagnosis was made on lung biopsy and there was rapid resolution after a course of prednisolone.