The control of onchocerciasis is not only a major success story in global health, but also one of the best examples of the power of public-private partnership at the international level as well as at the national level. The onchocerciasis story is also a leading example of the contribution of a group of Non- Governmental Organizations (NGO) called Non-Governmental Development Organizations (NGDO) to operational research which resulted in important changes in treatment strategies and policies.The four case studies presented here illustrate some key contributions the NGDOs made to the development of "community directed treatment with ivermectin" -CDTI, in Africa, which became the approved methodology within the African Programme for Onchocerciasis Control (APOC). The partnership between the international, multilateral, government institutions and the NGDO Coordination Group was the backbone of the APOC programme’s structure and facilitated progress and scale-up of treatment programmes. Contributions included piloting community-based methodology in Mali and Nigeria; research, collaboration and coordination on treatment strategies and policies, coalition building, capacity building of national health workforce and advocacy at the national and international level. While the Onchocerciasis Control Programme (OCP) and APOC provided leadership, the NGDOs working with the national health authorities played a major role in advocacy evolving the community methodology which led to achieving and maintaining- treatments with ivermectin for at least 20 years and strengthening community health systems.