BACKGROUND: A previous investigation showed an increased risk of testicular cancer among fire fighters in Wellington City, New Zealand, during the 1980s. Other studies of fire fighters had not identified testicular cancer as an occupational disease. METHODS: This was an historical cohort study of mortality and cancer incidence in all paid New Zealand fire fighters, from 1977 to 1995. RESULTS: The only cancer for which this study provided evidence of an increased risk was testicular cancer, even after excluding cases from the previous investigation. The standardized incidence ratio for 1990-96 was 3.0 (95% confidence interval: 1.3-5.90). There was no evidence that fire fighters were at increased risk from any particular cause of death. CONCLUSIONS: This study confirmed that New Zealand fire fighters are at increased risk of testicular cancer, although the reason is unknown. Other incidence studies of cancer in fire fighters are needed to confirm this finding.