ObjectivesTo develop a national standard level of blood pressure (BP) for Italian children on the basis of a large sample of the population.DesignWe analyzed data available from 21 Italian studies conducted according to the recommendations of the American Task Force between 1988 and 1994. Percentile curves of systolic and diastolic BP were constructed by fitting a third-order polynomial model of BP on age and height using multiple regression analysis.ParticipantsBP was measured in 11 519 healthy individuals (6258 boys and 5261 girls) aged 5–17 years in various locations throughout Italy. All measurements were performed at school.ResultsPercentile curves (5th, 10th, 25th, 50th, 75th, 90th and 95th) of systolic and diastolic BP are reported by age and by height for males and females.ConclusionsWith respect to the American standards, the levels in Italy for the 90th and 95th percentiles were 3–8 mmHg higher for systolic and diastolic BP in both sexes between 5 and 12 years of age, and 2–3 mmHg higher in older males. With respect to Northern Europe, in the lower ages, levels in Italy were quite similar, although slightly higher, whereas in late adolescence, the Northern European levels were much higher, especially in males, with differences of 4–5 mmHg for the mean values and 8–12 mmHg for the 95th percentile.