OBJECTIVE: To evaluate if using an international growth reference versus a national growth reference leads to differences in the prevalences of low weight-for-height (wasting) and low height-for-age (stunting) in a sample of children 8 to 14 years old. METHODS: A cross-sectional study was carried out with a sample of 1,470 school-children (both boys and girls) in the city of La Plata, in the province of Buenos Aires, Argentina. Based on the data on weight and height, Z-scores were calculated with regard to the reference values from the United States of America's first and second National Health and Nutrition Examination Survey (NHANES I and NHANES II), and the reference values for Argentina from the Argentine Pediatric Society. The prevalences of wasting and stunting were calculated, using as the cutoff point two standard deviations below the median of the reference. The prevalences were compared using the chi-squared test with Yates' correction, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: The international reference was positively associated with a higher prevalence of stunting in the entire sample (OR = 5.12; 95% CI: 3.27 to 8.05), in the boys (OR = 4.36; 95% CI: 2.43 to 7.93), and in the girls (OR = 6.32; 95% CI: 3.10 to 13.27). The prevalence of wasting was similar with both references. The distribution of height-for-age was skewed to the left with respect to the international reference and to the right with respect to the Argentine reference, while the distribution of weight-for-height overlapped both references. CONCLUSIONS: The differences in the prevalences of stunting calculated according to the two references that were used indicate a different nutritional status for the population studied. The increase in the height of the children with respect to the Argentine reference points to the presence of a positive secular trend, and the increase can explain part of the differences in the prevalence of stunting.