Patients with lung cancer present to and are managed by a variety of clinicians. In this study the effect of involvement by a respiratory physician on the diagnosis, staging, treatment and survival of a large unselected group of lung cancer patients was investigated. The study population was derived from the Scottish Cancer Registry. A total of 3,855 patients diagnosed during 1995 with lung cancer were studied. The data were validated and supplemented by references to medical records. The study found that a respiratory physician had been involved in the initial management of 2,901 (75.3%) patients. These patients were found more likely to have had the cancer diagnosis confirmed by histological methods and to have received active treatment with surgery, radiotherapy or chemotherapy. Survival, 1 yr after diagnosis was higher in patients who saw a respiratory physician (24.4 versus 11.1%) and benefit was found to have remained 3 yrs after diagnosis (8.1 versus 3.7%). Although the patients who had not seen a respiratory physician were generally older, and had more extensive disease, after correcting for age, stage and other prognostic factors, the relative hazard ratio of death for those not managed by a respiratory physician was 1.44. The data from this study supports the recommendations of recent lung cancer guidelines for the early involvement by a respiratory physician.