A population‐based case‐control study was carried out to follow up observations of increased lung cancer risk in the steel pouring areas of two Ontario steel mills. Study subjects were all men, aged 45–75 years, who died of lung cancer in the cities of Hamilton or Sault Ste‐Marie, Ontario from 1979–1988. Nine hundred sixty‐seven lung cancer victims were matched with 2,827 control subjects who died of other causes. Work histories were provided by the employers of steelworkers. In comparison with other residents of their cities, the relative risk of death from lung cancer was 0.85 (95% confidence interval [CI]: 0.58–1.23) for steelworkers in Sault‐Ste Marie and was 1.10 (95% CI: 0.89–1.37) for steelworkers in Hamilton. In internal comparisons within the steel companies, increased lung cancer risk was observed among foundry, coke oven, and pouring pit workers. Retrospective hygiene assessment suggested that the increased risk of lung cancer among steel pourers might be related to the use of tar‐based mold coating agents or to exposure to mineral fibers.