Latrine access alone may be insufficient to encourage households to dispose of young children's feces safely in a latrine, and little is known about the determinants of improved child feces disposal. We used longitudinal data collected at up to three timepoints for children less than 5 years of age from households in Odisha, India, which received a combined household-level piped water supply and sanitation intervention, but did not specifically promote the safe disposal of child feces. Among the 85% of intervention households who reported access to improved sanitation, we characterized child defecation and feces disposal practices by age, across time, and season, and assessed determinants of improved disposal. Feces from children less than 3 years of age was commonly picked up by caregivers but disposed of unsafely with garbage into open areas (56.3% of households) or in a drain/ditch (6.2%). Although children 3 and 4 years were more likely to use a latrine than younger children, their feces was also more likely to be left in the open if they did not defecate in a latrine. For children less than 5 years of age, most (84.7%) children's feces that was safely disposed of in a latrine was because of the children defecating in the latrine directly. Significant predictors for disposing of child feces in an improved latrine were the primary female caregiver reporting using a latrine to defecate, the child's age, and water observed at place for handwashing. These findings suggest that child feces interventions should focus on encouraging children to begin using a toilet at a younger age and changing the common behavior of disposing of young child's feces into open areas.