We study wealth disparities in the formation of anthropometrics, cognitive skills and socio-emotional skills. We use a sample of preschool and early school children in Chile. We extend the previous literature by using longitudinal data, which allow us to study the dynamics of child growth and skills formation. Also, we include information on mother's and father's schooling attainment and mother's cognitive ability. We find that there are no significant anthropometric differences favoring the better-off at birth (and indeed length differences at birth to the disadvantage of the better-off), but during the first 30 months of life wealth disparities in height-for-age z scores (HAZ) favoring the better-off emerge. Moreover, we find wealth disparities in cognitive skills favoring the better-off emerge early in life and continue after children turn 6 years of age. We find no concurrent wealth disparities for and socio-emotional skills. Thus, even though the wealth disparities in birth outcomes if anything favor the poor, significant disparities favoring the rich emerge in the early post-natal period. Mother's education and cognitive ability also are significantly associated with disparities in skill formation.