In developed nations it is part of the children's normal rights to go to school, but in developing nations including Nigeria, most school age children are not in school because it is not free and so it is not affordable. The number of out- of- school children in Nigeria according to UNESCO Institute of Statistics (UIS) is 10.5 million. One of the highest figure in the world. The most common factors for such a large number of out- of- school children are mainly poverty, cultural and religious beliefs as in the case of the girl- child and children with disabilities. This book is therefore of fundamental importance in contributing to the debate on how to guarantee a full implementation of the right to free primary education for all children in Nigeria. This is an urgent development priority which requires the need for immediate action by the Nigerian Government. It will also be a useful and relevant material for several other countries in Sub-Saharan Africa because they have similarexperiences, so they can learn from Nigerian experiences.