Tendulkar, a goodwill ambassador for the United Nations Children's Fund (UNICEF), was promoting the "wash in school" drive aimed at bringing down the death toll from poor sanitation.
He showed local children at a hotel here how to use soap and water to wash their hands before meals and avoid the risk of disease.
"My mother nvr allowed me to eat b4 washing hands! V must ensure all children learn such habits," Tendulkar was quoted as saying by official twitter handle of UNICEF Sri Lanka.
Sri Lankan cricket legend Muttiah Muralitharan was also present on the occasion and both took time out to play cricket with school students.