NGOs are voluntary social work organization who render help to government and society for improvement of quality of life of people and also animals. From education to health to environment…..and to poverty alleviation, the scope of NGOs operational areas touch every part of life. The NGOs have very less authority in decision-making, they drive their strength on the basis of their actions in right direction; they find governmental support in this, both financial and authoritative. Role of NGOs has grown substantially over the past century and they operate virtually in every part of the globe. This work deals with the forms of NGOs, their role in development of social system, implications with regard to finances, monitoring agencies, contributions to the United Nations and the limits and legitimacy of NGOs actions. The book is bound to attract the interest of social activists, policy planners, teachers and students of social work ad the NGOs.