We assessed a pilot project by UNICEF and Hindustan Unilever Limited to improve the quality of drinking water for children in schools through adoption of improved drinking water practices among households in southern India. The intervention consisted of providing classrooms of 200 schools a commercial water purifier, and providing basic hygiene and water treatment information to students, parents, and teachers. We found no evidence that the intervention was effective in improving awareness or uptake of effective water treatment practices at home. A similar proportion of household members in the intervention and control groups boiled their water (P = 0.60), used a ceramic filtration system (P = 0.33), and used a cloth filter (P = 0.89). One year after the launch of the campaign, household ownership of the commercial purifier promoted at schools was higher in the intervention group (26%) than the control group (19%), but this difference was not statistically significant (P = 0.53).