The cause of asthmatic attacks in a middle-aged man was disclosed and the relief of his symptoms achieved at one and the same time when he coughed up a tumour which proved to be a solitary bronchial papilloma. The pedicle of the tumour had ruptured as the result of infarction due to thrombosis in stromal blood vessels. Asthmatic attacks, stromal blood vessel thrombosis, and the coughing up of the tumour are three features which have not been reported in the few published accounts of this exceedingly rare bronchial tumour.