A historical cohort study of 406 workers was undertaken to evaluate the possible health hazards of employment in traditional electric power plants with particular regard to cancer mortality. The total mortality was below that expected [observed 40, standardized mortality ratio (SMR) 87] on the basis of national rates. Cancer mortality was slightly increased (SMR 112), mainly because of an excess of respiratory cancer (observed 9, SMR 171, 90% CI 89-299). Lung cancer deaths were higher than expected among those less than 60 years of age and among those with a duration of exposure and a latency period since first employment of over 10 years (observed 7, SMR 184). Furthermore, the increase was more pronounced among maintenance workers and workers in general services. Previous data indicated that there had been past exposure to some known respiratory carcinogens (ie, asbestos, polycyclic aromatic hydrocarbons). This study suggests that a possible lung cancer risk from traditional electricity generating plants should be considered and further studied.