A study of lung cancer among patients with beryllium (7440417) disease was conducted. The cohort consisted of 689 persons, 455 males, in the NIOSH Beryllium Case Registry (BCR). The BCR database included persons with documented evidence of beryllium exposure and clinically documented beryllium disease that was started by Massachusetts General Hospital in 1952 and taken over by NIOSH in the late 1970s. The vital status of the cohort was determined at the end of 1988. Death certificates were reviewed. Standardized mortality ratios (SMRs) were computed using rates for the United States (US) population as the reference. The smoking status of the cohort in 1965 was determined. A total of 428 deaths occurred in the cohort by the end of 1988. This yielded an SMR of 2.19. Twenty eight lung cancer deaths occurred, yielding an SMR of 2.00, a statistically significant increase. By sex, the lung cancer SMRs in females and males were 1.76 and 4.04, respectively. Both were statistically significant. Mortality from beryllium poisoning was significantly elevated, SMR 35.93. Pneumoconiosis mortality was significantly elevated, SMR 34.23. When categorized according to patients with acute or chronic beryllium disease, the lung cancer SMRs were 2.32 and 1.57, respectively. No other specific causes of death were significantly elevated. The cohort contained more former smokers and fewer current smokers than the general US population in 1965. Adjusting for smoking did not alter the lung cancer risk. The authors conclude that a two fold excess of lung cancer has been identified in male and female beryllium disease patients. The excess lung cancer mortality probably reflects exposure to beryllium, a suspected lung carcinogen. Beryllium disease itself could be a contributing factor to lung cancer.