Gold miners from Western Australia were surveyed in 1961. Data were collected on respiratory symptoms, smoking habits, employment history, and chest X-ray signs. Eighty-four percent of the men had smoked at some time, and 66% were current smokers. The prevalence of chronic bronchitis was over 20% at the time of the survey. A follow-up to the end of 1991 has been started which showed that, from 1969 to 1991, 999 miners died. Because vital status has not been ascertained for the whole cohort, a proportional mortality analysis was undertaken as a case-referent study. A strong effect of smoking on the risk of lung cancer was found, along with a slight, but nonsignificant increase in the lung cancer risk for the subjects employed underground for 40 years after adjustment for smoking. A complete follow-up and a full cohort analysis will enable these effects to be estimated more precisely.