A case-control study, undertaken to identify reasons for the exceptionally high rate of lung cancer among male residents of coastal Georgia, revealed a significantly increased risk associated with employment in area shipyards during World War II. The summary relative-risk estimate, adjusted for smoking, other occupations, age, race and county of residence was 1.6 (95 per cent confidence limits = 1.1 to 2.3). A synergistic relation was found between shipyard employment and cigarette smoking. These findings suggest that asbestos and possible other shipyard exposures during wartime employment account for part of the excess mortality from lung cancer in certain coastal areas of the United States.