In an attempt to study and prevent the development of hypertension, there is a growing interest in measuring blood pressure in children. The aim of this is to detect and monitor those with a relatively high level of blood pressure. Until now, reference values on blood pressure in children are based on data from North-American youngsters. The present study provides percentile charts based on pooled data from studies on blood pressure conducted in six North-West European countries among 28,043 children. These blood pressure centiles are presented as age-, height- and gender-specific. Brief guidelines for blood pressure measurements in childhood and for detection of children with a relatively high blood pressure are included.