As part of the Nutrition CRSP Mexico project conducted in rural villages in highland Mexico, this study examined whether nutritional factors, family characteristics, and the duration of schooling were associated with cognitive performances in 107 schoolers(53 boys and 54 girls) aged 8~10. Food intake was measured by recall, direct observation and weighment twice monthly over the course of a year. Families were characterized in terms of socioeconomic status and parental cognitive performance, education and aspiration. Dietary quality, but not energy intake, and anthropometry (wt-for-age, ht-for-age, head circumference) were significantly associated with cognitive test results for both verbal and performance measures. When the effect of SES is controlled using partial correlation, the relationships were substantially weakened. Sex differences were also found in response to nutritional deprivation. Among boys, dietary quality was the most important indicator of cognitive performance, while household economic conditions were more importantly associated with cognitive performance among girls. Participation in schooling was important for cognitive skille as it related to nutritional status.