Environmental risk factors can play an important and immediate role in limiting early childhood development in low- and middle-income countries (LMICs). Forty-three percent of children under five years in LMICs are at risk of not meeting their developmental potential, with children in sub-Saharan Africa being at greatest risk. Children under age three years are particularly vulnerable due to their rapid brain development and sensitivity to nutrient effects on growth, cognition, and school attainment. Climate and weather shifts can also drive disease patterns, like the spread of malaria. Environmentally-driven food security, dietary patterns, and malaria are understudied in relation to early childhood development. However, these factors may be associated with developmental outcomes among children before the age of five years due to their hypothesized impacts on nutrition, brain growth, and overall health with lifelong and intergenerational implications. Kenya has a large rural population facing challenges adapting to climate change and coping with food insecurity. While the country has a national early childhood development policy, much of the curriculum focuses on preschool-aged children and measures of early childhood development in Kenya are limited and vary by region, measure or domain assessed, and cultural differences. About one-quarter of Kenya’s population is chronically food insecure and levels of stunting and underweight in rural areas, western Kenya, and around Lake Victoria are high. Malaria is also endemic in Kenya and a leading cause of child morbidity and mortality. Kenya therefore serves as an optimal place to study associations between food insecurity, children’s fatty acid and fish intake, malaria, and early childhood development.