In 2003, the Public-Private Partnership for Handwashing with Soap (PPPHW) was created in Senegal with technical assistance from the Water and Sanitation Program (WSP). Housed initially within the Office Nationale de L'Assainissement, the government unit overseeing sanitation within the Ministry of Health, the PPPHW's main objective was to catalyze and coordinate multi-sectoral involvement in the promotion of handwashing with soap. This learning note serves to document the behavior change component of the project in Senegal, including key strategies, results, challenges, and lessons learned.