Summary 1. We have established growth curves for the first year of life on 654 Negro infants observed in private pediatric practice. These infants were from families in the lower middle class. 2. The mean birth weight for the male and female infants was 7.66 pounds and 7.20 pounds, respectively. The mean length at 1 month of age for male and female infants was 21.1 inches and 20.9 inches, respectively. 3. At 12 months of age the weights attained were 22.59 pounds for male infants and 21.33 pounds for female infants. At 12 months of age the mean height for males was 29.8 inches and 29.5 inches for females. 4. So far as we know, our report on growth in height for the first year of life is the first to be reported on Negro infants from middle-class families. 5. We compared our results with data on Negro infants from various economiclevels (general population, indigent, low middle class) reported in the literature. The infants in our study and those reported by Bakwin and Patrick surpassed those of other series in growth throughout the first year of life. A significant difference in growth was observed when indigent infants were compared with infants from middle class levels. 6. We also compared our data with similar reports on the growth of white infants. There was no significant difference between the growth curves of Negro and white infants from comparable economic levels.