A study of the physical condition at birth of 68 siblings (57 second, 10 third siblings and one fourth sibling) born to 57 of the women studied in a previously published series of cases has been made in relation to the mean general dietary rating for the latter part of these subsequent pregnancies. 1. In the 284 cases when the maternal diet was “excellent or good,” 95% of the infants were in good or excellent physical condition at birth and only 5% were in either fair or poorest physical condition. In contrast, when the maternal diet was “poor to very poor” 65% of the infants were in the poorest physical condition at birth and 27% were in fair condition, while only 8% were in either good or excellent physical condition. 2. The “fair” diet group was divided into two groups, thus giving 4 maternal dietary groupings: (1) “excellent or good”; (2) “fair”; (3) “poor”; and (4) “very poor.” This has helped to make clear that a “very poor” maternal diet is associated with an infant in the poorest physical condition at birth, while an “excellent or good” diet is associated with an infant in excellent or good condition at birth. The consistent shift in physical condition of the infant with each change in dietary rating in either direction is impressive. 3. The statement still remains true that all of the stillborn infants, all of the neonatal deaths but one, all of the premature infants but one (a neonatal death), all of the functionally immature infants, and most of the congenital defects were found in the group of infants born to mothers with “poor” or “very poor” prenatal diets. Since no major effort was made to change the dietary habits of these women, it is probable that in the majority of the cases the prenatal dietary rating was representative also of long-time food habits. 4. The average birth weight and birth length of the infant decreased as the maternal dietary rating became poorer. The constancy of this relationship is impressive. While a relationship exists between physical condition of infant and birth weight and length, a closer relationship is shown between maternal dietary rating for pregnancy and birth weight and length of infant. 5. Data were presented on 53 matched pairs of siblings. Improvement of the infant's condition with improvement of the maternal diet and deterioration of the infant's condition with deterioration of the maternal diet appeared in this series where each of the 53 mothers was observed through two pregnancies. While the changes were not sufficiently striking to be statistically significant, it is felt that this series of matched siblings is unique since it has been possible to use each mother as her own control and thus in part minimize hereditary and environmental variables which influence the condition of babies at birth. Similar studies of women through successive pregnancies may help further to clarify the relationship between prenatal diet and the condition of the infant at birth.