Anthropometric measurements were obtained within 12 h of birth in 52 infants of non-diabetic mothers and 61 infants of diabetic mothers. Most of the diabetic patients were under good control, only ten of 61 having postpartum hemoglobin A1c levels in excess of normal. Neonates were grouped as normally-grown or macrosomic. Birthweight, crown-heel length, head circumference and skinfold thickness were measured. In each diabetes class, macrosomic neonates had larger mean length, head circumference and skinfold thickness than their normally-grown peers. At equal birthweight, neonates of gestational diabetic mothers and of non-diabetic mothers were similar in length, head circumference and skinfold thickness. Neonates of permanently insulin-requiring diabetics were similar to their non-diabetic peers in length and head circumference but had thicker skinfold thicknesses. Anthropometric measurements do not permit differentiation of the origin of neonatal macrosomia.