Three recent cases of berylliosis are reported, and occupational aspects of the disease are reviewed. Three cases of chronic beryllium (7440417) disease diagnosed between 1978 and 1980 occurred in machinists who fabricated beryllium metal parts for missile guidance systems in a large aerospace manufacturing facility. A review of environmental survey data suggests that exposure to beryllium dust exceeded prevailing occupational exposure standards during the 1960s and early 1970s. A brief history is given of the recognition of occupational berylliosis and its decline with control of exposure. It is noted that, although use of beryllium in fluorescent lighting tubes was discontinued in 1949, major consumption of the element occurs in the nuclear and aerospace industries, in electrical applications, and in the manufacture of many electronic devices. Similarities between sarcoidosis and berylliosis are examined, and differential diagnosis is discussed. The authors conclude that the potential for beryllium disease still exists. Physicians can play a role in the continued control of the disease by reporting any suspect cases to the US Beryllium Case Registry.