To identify which parameter showed the strongest correlation with neonatal body fat store, when the ratios for assessing both weight‐for‐length and the mid‐arm circumference to head circumference (MAC/HC) were included in the analysis, body anthropometrics and skinfold thickness were measured in 250 full‐term and 125 preterm infants. Among the study cases, 66.7% were appropriate for gestational age, 26.7% were small for gestational age and 6.7% were large for gestational age. Sum of the skinfold thickness measured at the midtricepital and subscapular areas correlated well with body anthropometrics, weight/length ratio, body mass index, ponderal index and mid‐arm circumference to head circumference ratio. Multiple stepwise regression analysis revealed that the weight/length ratio correlated best with skinfold thickness in both full‐term and preterm newborn infants. Therefore, the simple weightllength ratio might be useful for evaluation of the nutritional status of intrauterine growth, and in the prediction of metabolic complications in both full‐term and preterm newborns with abnormal intrau