Objectives: Recent studies have concluded that acupuncture is safe in the hands of a qualified practitioner. This study assessed the risk of adverse effects of acupuncture administered during pregnancy. Methods: 593 women with nausea and vomiting in early pregnancy volunteered to participate in a randomised controlled trial, conducted at the Women's and Children's Hospital, in South Australia. Patients were given either traditional acupuncture, formula acupuncture, sham acupuncture or no acupuncture. Outcome Measures: Data were collected on perinatal outcome, congenital abnormalities, pregnancy complications and the newborn. Results: No differences were found between study groups in the incidence of perinatal outcome, congenital abnormalities, pregnancy complications and other infant outcomes. Conclusion: Our findings suggest that no serious adverse effects arise from acupuncture administered in early pregnancy.