In 2003 the Municipal Health Service in Amsterdam started to screen pregnant women for HIV according to the opting-out method. In this method the HIV test is routinely included in the prenatal screening along with hepatitis B virus (HBV) and syphilis. If the woman does not want to be tested for HIV then she must actively opt out of this test. This screening method was chosen because in the universal screening method used in 2002, women had to give their explicit consent to test for HIV and this led to a high refusal rate (13.6%), especially among women from AIDS-endemic countries. After the introduction of the opting-out method, the refusal rate fell from 3% in the first quarter of 2003 to 1.4% in the last quarter of 2003. None of the women refused to be tested for HBV or syphilis. In 2003, the HIV prevalence among pregnant women was 0.3% (35/13.621). The experiences with this screening method in Amsterdam were used to implement the national opting-out method for HIV screening in pregnant women, which was introduced on 1 January 2004.