Many developing countries are now facing the ethical challenges of regulating embryonic stem cell research. In Latin America the recent Brazilian Supreme Court decision allowing such research in the country was the first case in the region. There are other countries in Latin America with the scientific capacity to develop embryonic stem cell research, but they do not have the laws or regulations that would allow this research, as is the case in Argentina and Mexico. However, the main challenges for developing countries are not solely the technological conditions or the legislation, but also the religious pressures against research with human embryos. It is worth remembering that abortion is against the law in many developing countries with the potential to conduct stem cell research. Differently from developed countries, where the political debate about abortion was conducted before the emergence of embryonic stem cell research, in developing countries both debates are being conducted simultaneously.