Objective: To describe the knowledge, attitudes and practices of prenatal care providers in relation to prenatal HIV testing. Methods: A stratified random sample of 784 family physicians, 200 obstetricians and 103 midwives providing prenatal care in 3 health planning regions in Ontario received a questionnaire. Results: Response was 622/1087 (57%). Almost half of participants (43%) were not aware of Ontario's prenatal HIV testing policy. Eighty-five percent of participants reported that they offered or ordered HIV testing for all pregnant women. Sixty-six percent agreed that women should have a choice about whether to test or not, and midwives were more supportive of having an informed consent process than were physicians. Conclusion: Knowledge about the risks and benefits of prenatal HIV testing needs to be improved, and standards for informed consent should be re-evaluated to achieve the most ethical process with the least complexity. La traduction du résumé se trouve à la fin de l'article.