There has been little examination of: (1) associations of early-life nutrition and adolescent cognitive skills, (2) if they vary by gender, (3) if they differ by diverse contexts, and (4) contributions of post-infancy growth to adolescent cognitive attainment. We use Young Lives data on 7687 children from Ethiopia, India, Peru, and Vietnam to undertake ordinary least squares estimates of associations between age-1 height-forage z-score (HAZ) and age-15 cognitive outcomes (math, reading, vocabulary), controlling for child and household factors. Age-1 HAZ is positively associated with cognitive scores in all countries. Child gender-specific estimates for these coefficients either do not differ (math, reading) or favor girls (vocabulary). Augmenting models to include growth in HAZ between ages 1 and 15 years that was not predicted by HAZ at age 1 reveals that such improvements are associated with higher cognitive scores, but that sex-specific coefficients for this predictor favor boys in India and Peru. The results suggest that nutritional indicators at age 1 have gender-neutral associations with math and reading and favor girls for vocabulary achievement at age 15, but unpredicted improvements in HAZ by adolescence are associated with higher cognitive scores for boys than for girls. This evidence enriches our understanding of relationships between children's nutritional trajectories during childhood and adolescent cognitive development, and how these associations vary by gender in some contexts to the possible disadvantage of girls.