Sexual differences in anthropometric measurements have been studied in a sample of 17,787 preterm and full-term infants, born between 1980 and 1990 in the maternity of Clamart Hospital (Hauts-de-Seine, France). Body weight, body length, head and chest circumferences were found significantly larger in male newborns. Conversely, the subscapular and tricipital skinfold thicknesses had higher values in females. Such greater fatness in females could be related to the better outcome in neonates of this sex. The weight-for-height indices, however, did not show this female advantage: the body mass index (BMI) and the body weight/body length index were greater in male neonates, the ponderal index (PI) showed no sexual difference.