OBJECTIVE: To investigate the possibility that environmental agents contribute to the pathogenesis of Wegener's granulomatosis (WG). METHODS: We undertook an extensive search for possible environmental exposures by developing a comprehensive questionnaire that was administered by telephone interview to 53 patients with WG and 2 control groups: one with osteoarthritis and the other with gout. Questions focused on hobbies and vocations, work, home, and allergies. Exact logistic regression was used to calculate odds ratios and 95% confidence intervals after adjusting for potential confounders. After adjusting for age and sex, data are reported for all exposures with odds ratios >2.0 against either control group or for any allergic propensity. RESULTS: Results suggest that mercury and perhaps lead exposure were positively associated with WG as compared with either control group, although the number of patients exposed was small. A prior history of allergy was also associated with WG as compared with either control group. CONCLUSION: We conclude that heavy metal exposure and a prior history of allergy may play a role in the etiopathogenesis of Wegener's granulomatosis.