Objectives:to analyze the accuracy of neck circumference (NC) as a measure for assessing excess body weight in children aged 13-24 months of life, according to gender.Methods:this is a cross-sectional study comparing the neck circumferences in relation to body mass index (BMI) and other anthropometric measures. The best cut-off point for identifying excess body weight was determined using the Receiver Operating Characteristics curve (ROC curve), according to gender and age groups 13-15 months, 16-19 months and 20-24 months.Results:NC waspositively correlated (p<0.001) with body weight and BMI in both genders, and length in girls (p<0.001). Positive correlations were found between NC and BMI in the three age groups (13-15, 16-19 and 20-24 months) in both boys and girls. The NC cut-off points for boys were 23.6, 23.9 and 24.0 cm, and 23.4, 23.5 and 23.6 cm for girls, for the 1315, 16-19 and 20-24 age groups respectively.Conclusions:NC can be used to screen for excess body weight in children aged 13-24 months. However, further studies with a larger sample will be required in order to complement these results.