In most developed countries, the epidemiological disease profile has changed from infectious to degenerative, causing major alterations in epidemiological thinking and public health policies. Less developed nations have to deal with a more complex situation, because social disparities create highly unequal health conditions, the affluent being afflicted by degenerative conditions, whereas the poorer social segments continue to suffer infectious diseases, but also begin to feel the effects of chronic illness. At the turn of the 21st century, equity in health care is not being served, and social justice has lost credibility as a conceptual driving force of public health policies. Rampant injustice confirms that theories, reality and suggested practices of just social orders are flawed, leaving the needy without help or hope in a world of flagrant ethical inadequacy. And yet, mainstream bioethics loses meaning and relevance as it clings to the principle of justice and hails such concepts as global justice and universal health-care equity, misleadingly focusing on justice as a desideratum. This book pleads for an urgent turn towards directly addressing injustice as a reality that requires pressingly needed arguments and proposals to inspire realistic public health policies and programs based on an ethics of protection. Ever since Hobbes, all shades of political philosophy accept that the basic obligation of the ruling power is to protect its subjects. The ethics of protection emphasizes aiding the needy and the disempowered in obtaining access to basic goods and services related to health-care. Public health is called upon to fulfill protective obligations to guarantee disease prevention and medical services to the population, taking special care to safeguard those unable to cover their health-care needs in market-oriented medical services and institutions. The bioethics of protection developed in this text presents specific and explicit guide-lines to assure that protective public health actions be efficacious (problem-solving), efficient (sustainable cost/benefit relation) and ethically sound (respecting human rights and the common weal). These guide-lines are designed to give ethical support and justification to public health policies even when they require some unavoidable limitations of individual autonomy to promote social health benefits.