Screening for hepatitis B is routinely performed in most antenatal clinics. Whether the same should occur for hepatitis C needs to be assessed for each population by determining the prevalence of this infection within the community and whether any particular high-risk group can be identified. A series of 2,000 consecutive patients attending for antenatal care at the Mercy Hospital for Women, Melbourne, was tested for evidence of hepatitis C infection. The prevalence of hepatitis C infection in this group was 1.45% (95% confidence interval 0.97-2.1%). Significant independent risk factors were a history of intravenous drug use, blood transfusion and previous pregnancy ending prior to 20 weeks' gestation. Currently no treatment exists for hepatitis C and as there are no effective means of preventing transmission to the baby, routine screening cannot be justified in view of the low prevalence of this infection among antenatal patients. Selective screening of patients with relevant risk factors for hepatitis C should be carried out as the most efficient and cost-effective strategy in pregnancy.