Worldwide, 892 million people practice open defecation, most of whom live in rural areas of South Asia and Sub-Saharan Africa. Community-Led Total Sanitation (CLTS) is the most widely deployed approach to generate demand for, and use of sanitation facilities. CLTS relies on behavioral change and community self-enforcement to end open defecation. Since its genesis in Bangladesh in 1999, CLTS has spread to approximately 60 countries, mostly in Asia and Africa, and is employed by the majority of development organizations operating in rural sanitation. This paper uses a qualitative approach to analyze the reasons and processes that drove the wide diffusion of CLTS. We show that CLTS was embraced because it was perceived as a fast and effective solution to the problem of open defecation, one which was in line with the decentralization and community participation paradigms, at a time when donors and governments were looking for strategies to meet the MDG for sanitation. CLTS spread under the leadership of influential donors, NGOs, persuasive practitioners, and academics. Face-to-face interactions among members of this network and local governments at conferences and workshops played a central role in the diffusion of the approach. The use of experiential learning during study tours and workshop field visits has been crucial to persuade government actors at different levels, NGOs, and donors to use the CLTS approach. Notably, robust scientific evidence played little role in the diffusion of CLTS. We conclude by making suggestions to strengthen the evidence base for rural sanitation policies.