To trace growth charts for height, weight and body mass index (BMI) that apply to the whole Italian population. Different charts were drawn for central-north and south Italy since children in central-north regions are known to be taller and leaner. Cross-sectional study. A sample of schoolchildren covering 16 of the 20 Italian regions, with data collected between 1994 and 2000. A total of 27 421 girls and 27 374 boys, aged 6-20 y. Height and weight were measured using portable Harpenden stadiometers and properly calibrated scales, respectively. SIEDP references are presented both as centiles and as LMS curves for the calculation of standard deviation scores. According to International Obesity Task Force, SIEDP charts for BMI include the limits for overweight and obesity, ie the centiles having, at 18 y of age, the value of 25 and 30 kg/m(2), respectively. The comparison between SIEDP and Tanner et al's charts for height, still in use among most Italian paediatricians, shows that before puberty Italian children are 2-4 cm taller than their English peers. Because of these differences, Tanner's charts fail to detect, when applied to Italian children, 50-90% of short children aged 6-11 y, ie with stature below the 3rd centile of their reference population. Rolland-Cachera et al's centiles for BMI are lower than those of SIEDP standards, mainly during adolescence (up to 6.6 kg/m(2) for the 97th centile), and apply poorly to Italian children. The prevalence of overweight is 27 (boys) and 19% (girls) in south Italy vs 17 (boys) and 10% (girls) in central-north Italy. These references intend to supply Italian paediatricians with a tool that avoids the use of outdated or inadequate charts, and thus should be suitable for monitoring their patients' growth. Italian Society for Pediatric Endocrinology and Diabetes (SIEDP).