We studied all cases presenting during life with carcinoma of the bronchus and registered at the Yorkshire Regional Cancer Registry 1976-1983. During this period fibreoptic bronchoscopy became more widely available in the region, and multiple drug chemotherapy became first line treatment for small cell carcinoma. Although there was little change in the overall incidence of lung cancer during the study period, the proportion of females increased by 4.8% and the mean age at presentation rose by 2.3 years. The histological confirmation rate rose by 29% from 45% to 58%. The proportion of patients with small cell carcinoma treated by chemotherapy increased from 17% to 39%. With this exception therapeutic intervention rates were unaltered. The prognosis of patients with small cell carcinoma treated by chemotherapy improved, particularly so for those less than 60 years. There was a consistent trend for an overall improvement in survival in other groups, and this was significant for those aged 70 and over where it appeared to be related to more appropriate management of squamous cell carcinoma. We conclude from this regional study that increased diagnostic activity in District General Hospitals has allowed an improvement in prognosis both for patients with small cell carcinoma treated by chemotherapy, and in patients over 70 with non-small cell cancer. These trends can be expected to continue over the next few years.