The smoking habits of 202 patients presenting with sarcoidosis, as recorded in the clinical case records, were compared with figures from the General Household Surveys (GHS) to determine whether there was any association between smoking habit and sarcoidosis. In 19 there was no record of smoking habit. Of the remaining 183 patients, 40 (21.9%) were smokers, which was significantly less than expected from the GHS figures (p less than 0.001). This association between non-smoking and sarcoidosis persisted despite further analysis by sex and age distribution and socioeconomic grouping. Statistical likelihood models showed that ex-smokers were similar to current smokers with respect to the association between smoking and sarcoidosis. This association was greatest in those patients with stage I sarcoidosis and less for those with other stages of the disease.