PIP: It was published almost 3 years ago that zidovudine administered orally to HIV-infected pregnant women, intravenously during labor, and later administered to newborn infants reduces the incidence of HIV infection in infants by two-thirds. This regimen, known as the ACTG 076 regimen and capable of saving the life of one of every seven infants born to HIV-infected women, subsequently became the standard of care in the US. However, the high cost of zidovudine and the ACTG 076 regimen impedes their use in developing countries. A regimen as effective but less expensive than ACTG 076 is therefore highly desirable in countries worldwide, but especially in developing countries. The authors oppose the use of placebo-controlled trials as unethical in the search for alternative antiretroviral drug regimens to prevent the perinatal transmission of HIV. 15 trials in developing countries are identified in which some or all of the participants are not being provided with antiretroviral drugs. Those studies violate recent guidelines designed specifically to address ethical issues regarding studies in developing countries. An urgent need exists to develop and adhere to a universally recognized code of ethics for medical research upon human subjects.