Nutrition plays an important role in the development of a child, particularly in low- and middle-income countries where malnutrition is often widespread. The relation between diet, hemoglobin, nutritional status, motor development, stimulation and mental development was examined in a cross-sectional sample of 1,079 children 12-18 months of age living in rural Bihar, India. Path analysis revealed associations between (a) length-for-age z-scores and motor development, standardized ß (ß) = 0.285, p < 0.001, and (b) motor and all mental development outcomes (language: ß = 0.422; personal-social: ß = 0.490; memory: ß = 0.139; and executive function: ß = 0.072, all p < 0.001). Additionally, stimulation was significantly associated with language scores and hemoglobin concentration with memory. These findings inform interventions aimed at improving child development in Northern India.