The success of national development is determined by availability of qualified human resources, which is essentially determined by nutritional status. About 1.3 milion malnourished children are predicted to lost around 22 million IQ points. Early malnutrition is known to have a great impact on later growth and development. The objective of this study is to investigate the incidence of malnutrition among children age under two years and post two years and their effect on verbal and numeric learning performance. This retrospective cohort study which was conducted on 1200 children shows consistent results that the earlier a child experienced malnutrition the lower the performance. The risk of having low verbal performance among malnourished children were 25 (children age under two years) and 15 times (children more than 2 years) greater compared to those of normally nourished children. Verbal performance is related to longlife nutrition status while numeric performance is more related to the first five-years of life. Good nutrition status could prevent low verbal performance of 44% and 30% for children under 2 year of age and children more than 2 year, respectively and help prevent 80% and 63% of low numeric performance.