We examine the influence of the relative good health at birth in the Mexican American population on their subsequent well-being. Using the National Longitudinal Survey of Youth Child Data (NLSY-CD), we conduct a comparative analysis of child development among Mexican American, non-Hispanic black, and non-Hispanic white children ages 3 and 4 (N = 3710). We use the Peabody Picture Vocabulary Test-Revised (PPVT-R) as our operationalization of child development. Descriptive results suggest that, unlike the relative similarity in the rates of low birth weight between the white and Mexican American populations, Mexican Americans have much lower developmental outcomes. Multivariate analysis shows that birth weight is not a powerful predictor of child development, nor does it explain pronounced racial and ethnic differences. Mother's education, poverty, and immigrant status of parents remain significantly more important in the developmental process of all children in our sample.Although the relatively favorable birth outcomes of Mexican American infants have been studied extensively, the extent to which good health at birth affects their subsequent health and well-being has received little attention. Mexican American women have remarkably good birth outcomes compared to other populations in the U.S. of similar socioeconomic backgrounds, notably non-Hispanic blacks, and