Abstract Introduction The references used to assess child growth in Spain are the graphs of the Orbegozo Foundation and the charts of the World Health Organization. The objective of this study is to analyze the differences between the two charts for weight, height and body mass index, and assess their relevance to identify growth or nutritional problems. Material and methods The values of the extreme percentiles of height, weight and body mass index for each sex from 0 to 10 years in both charts are compared. For each value Absolute differences and Z scores are calculated for each value. To evaluate the impact on the prevalence of the various nutritional or growth disorders the location of the value of the respective percentiles of in each of the charts were assessed. Results Significant differences were observed between the 3th percentile of height and weight, 97th of weight, and 85th and 97th of body mass index. Marked differences were observed for the extreme values of body mass index. During the first years, the Orbegozo charts overestimate the prevalence of malnutrition (between 2% and 19% depending on age and sex) compared to the WHO charts. In subsequent ages Orbegozo underestimates WHO between 0.7% and 2.89 %. Orbegozo underestimates the prevalence of overweight (between 2.5% and14.8 %) compared to the WHO charts. The 97th percentile of Body mass index in the Orbegozo charts corresponds in most cases with WHO percentiles above 99.99 %. Conclusion The two charts analyzed have significant differences from a clinical and the public health point of view, in the estimation of overweight/obesity and malnutrition.