This is a report on the socioeconomic background, dietary intake, and mother-child interaction of children who are on or below the third percentile curve and a contrast group on or above the 25th percentile curve for height and weight of the Boston Growth Standards. Gross family income did not differentiate between groups at a statistically significant level; however, the taller and heavier children came from families of higher socioeconomic standing as indicated by the significant differences in the scores of both groups on a socioeconomic index comprised of per capita income, maternal education, presence of a male in the household, and household density. Also in comparison to the underweight and undersized children, the contrast group exhibited higher calories, protein, iron, niacin, and ascorbic acid intake and was more likely to have more frequent and more positive contact with the mothers.