Family planning is a human right. Yet today some 222 million women in developing countries are unable to exercise that right because they lack access to contraceptives, information and quality services or because social and economic forces prevent them from taking advantage of services even where they are available. The State of World Population 2012 explains why family planning is a right, examines the challenges in ensuring that all women, men and young people are able to exercise that right and suggests actions that governments and international organizations can take to give everyone the power and the means to decide freely and responsibly how many children to have and when to have them.