Poor water quality and sanitation are leading causes of mortality and disease in developing countries. However, interventions providing toilets in rural areas have not substantially improved health, likely because of incomplete coverage and low usage. This paper estimates the impact of an integrated water and sanitation improvement program in rural India that provided household-level water connections, latrines, and bathing facilities to all households in approximately 100 villages. The estimates suggest that the intervention was effective, reducing treated diarrhea episodes by 30-50%. These results are evident in the short term and persist for 5 years or more. The annual cost is approximately US$60 per household.