Objectives: To examine the relationship between occupational exposures and spontaneous abortion in female veterinarians.Methods: The Health Risks of Australian Veterinarians project (HRAV) was a questionnaire-based survey of all graduates from Australian veterinary schools from 1960 to 2000. Of 5748 eligible veterinarians sent the questionnaires, 2800 replied including 1197 females (42.8%). The response rate was 59% of women veterinarians eligible to participate. The pregnancy of women was defined as the unit of analysis. We restricted analyses to pregnancies of those women who reported being employed when the pregnancy began and were working only in clinical practice. Of 1355 pregnancies, 940 were eligible for the final analysis. Self-reported occupational exposures to anaesthetic gases, x rays, pesticides and long working hours in relation to spontaneous abortion were examined.Results: In a multiple logistic regression controlling for 12 potential confounders, there was a more than twofold significant increase (OR 2.49, 95% CI 1.02 to 6.04) in the risk of spontaneous abortion in women exposed to unscavenged anaesthetic gases for >= 1 h per week. Veterinarians who reported performing more than five radiographic examinations per week had a statistically significant elevated risk of spontaneous abortion compared to those who performed five or less (OR 1.82, 95% CI 1.17 to 2.82). There was also approximately a twofold significant increased risk of spontaneous abortion in women who used pesticides at work (OR 1.88, 95% CI 1.18 to 3.00).Conclusion: Female veterinarians, particularly those of childbearing age, should be fully informed of the possible reproductive effects of unscavenged anaesthetic gases, ionising radiation and pesticide exposure and reduce their exposure by using protective devices when they are planning to become pregnant and during pregnancy.