Sanitation is one of the most critical issues that developing countries face. Worldwide, about 2.5 billion people lack adequate sanitation facilities, and each year about 700,000 children die from diarrhea. One noteworthy effort to solve this problem is the Reinvent the Toilet Challenge, which the Bill & Melinda Gates Foundation launched in 2011. Did the Gates Foundation incorporate research findings of this kind into the framing of its sanitation initiative? To what extent, that is, does the Reinvent the Toilet Challenge build on what scholars have previously discovered about sanitation in developing countries? In posing such questions, we don’t mean to suggest that the foundation neglected to conduct due diligence before it rolled out this initiative. Our purpose, rather, is to highlight the importance of basing philanthropic programs on a body of shared knowledge.