This book examines an important but neglected topic: environmental NGOs in sub-Saharan Africa. Although there is increasing emphasis on the potential of NGOs for solving Africa's environmental and development problems and strengthening civil society, research raises questions about NGO effectiveness. Based on a survey of research from across Africa and an intensive study of 52 Cameroonian environmental NGOs with diverse goals and social and ecological contexts, this book argues that understanding environmental NGOs' potential contributions requires both studying diverse NGO types and applying appropriate theory. In contrast to 'top down' theories of civil society or the 'environmentalism of the poor'-which assume that NGOs will fit into the niches the theories envision for them-the authors apply theories of organizations to examine how NGOs' efforts to promote sustainable development are affected by their funding, management strategies, and relationships with government, communities, and other NGOs. Research results challenge conventional wisdom about the conditions under which environmental NGOs can solve environmental problems, strengthen civil society, and participate in social movements. The authors explore the implications of this for theory and offer practical and innovative suggestions for increasing NGOs effectiveness.