Occupational exposure to potentially hazardous agents may increase the risk of spontaneous abortion. The present study addresses the frequency and risk for miscarriage among dental surgeons compared to those of high-schoolteachers and non-employed women. A self-administered postal questionnaire was mailed to all dental surgeons registered in the Norwegian Dental Association (n=1320), and to a random sample of high schools teachers(n=1084), recruited from the registry in the Norwegian Educational Association.