Health researchers face an intriguing puzzle: Despite a high level of development, Indian children are among the most severely malnourished worldwide. One hypothesis is that large portions of the Indian population defecate in “open space” outdoors, exposing children to bacteria that can cause diarrhea, infection, and poor nutritional status. We test this hypothesis using new data from the South India Community Health Study in Tamil Nadu undertaken in 400 villages. Combining measures of toilet facility usage and GPS coordinates of households with anthropometric data from 2500 children ages 0-10, we examine the relationship between neighborhood-level measures of open defecation and child nutritional status. We also test a “gendered hygiene hypothesis,” which argues that girls have better nutritional status than boys due to cultural restrictions in their everyday movements. Hence, we expect the negative association between community measures of open defecation and nutritional status will be less strong for girls.