Past research suggests robust positive associations between household socioeconomic status and children's early cognitive development in Western countries. Relatively little is known about these relations in low-income country settings characterized by economic adversity, high prevalence of malnutrition and infectious disease, and relatively lower school enrollment. The present study develops and empirically evaluates an adapted model of early childhood development using a sample of 2,711 Zambian 6-year-olds. Early learning in and out of the home was found to explain much of the relation between socioeconomic status and children's cognitive skills, including language, nonverbal reasoning, and executive function. Child height-for-age (a proxy for overall nutritional status and health) was also predictive of children's cognitive skills and both early and on-time school enrollment. Implications for global child development, intervention, and future work are discussed.