OBJECTIVE: Our purpose was to determine physician attitudes regarding voluntary versus mandatory status of human immunodeficiency virus testing in pregnant women. STUDY DESIGN: A questionnaire was sent to a sampling of the membership in District IX of The American College of Obstetricians and Gynecologists. Members were queried about experience with pregnant patients who were human immunodeficiency virus positive. Practice characteristics were sampled, as were experiences with antiviral agents in pregnant women. RESULTS: Physician attitudes were influenced by their type of medical practice environment. Bioethical considerations were further influenced by data reflecting zidovudine use in pregnant women. Two thirds of respondents favored mandatory human immunodeficiency virus testing of all pregnant patients. More than 90% favored public health reporting of all human immunodeficiency virus - positive patients. One quarter of respondents were not current on California human immunodeficiency virus codes. A persistent percentage do not offer human immunodeficiency virus counseling or testing. CONCLUSION: Considerable physician support exists for mandating human immunodeficiency virus testing in all pregnant patients as the primary means of decreasing maternal-fetal human immunodeficiency virus transmission and the considerable resulting costs. (Am J Obstet Gynecol 1996;174:1750-6.)