BACKGROUND: Self-expanding metal stents have been used successfully to overcome large airway obstruction due to malignant pulmonary disease. The technique has been modified to place stents under direct vision using the fibreoptic bronchoscope. The effect of this procedure on lung function and patient well being was investigated in a large series of patients. METHODS: Fifty six patients with malignant tracheobronchial tumours were treated for symptoms of life threatening airways obstruction or collapse of a lung by the insertion of an expandable metal stent(s) under local anaesthetic using a fibreoptic bronchoscope. All had inoperable cancer and 33 had relapsed after or failed to respond to radiotherapy, chemotherapy, or surgery. Forty seven had primary bronchial carcinomas and nine had metastases from other tumour sites. All but two patients had the stents inserted at one sitting. Measurements were performed in most of the patients before and after stenting and included objective measures (pulmonary function tests, arterial blood gas tensions) and non-objective measures (patient well being, performance status). RESULTS: Overall, 77% of patients showed symptomatic improvement. In those patients in whom measurements were performed two thirds showed improvement in forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow rate (PEFR) and arterial oxygen tension (PaO2). Medical Research Council dyspnoea score (MRC), Karnofsky, and visual analogue scores (for both breathing and well being) improved in 81% of patients. There were no perioperative deaths. Fifty one patients have died since the procedure with a mean survival of 77 days (range 1-477), and five patients are still alive after a mean of 207 days (range 135-274). CONCLUSIONS: In suitable patients with either extraluminal or intraluminal tumour, or both, the insertion of expandable metal stents using a fibreoptic bronchoscope and local anaesthetic is a valuable addition to other palliative therapies in the treatment of lung cancer.