Hypertension is one of the main risk factors for cardiovascular disease and ranks among the leading causes of morbidity and mortality worldwide. Hypertension in children is rare, but the blood pressure rank in relation to peers is often maintained from childhood into adulthood and is therefore of great public health relevance. For this reason, one of the aims of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) was to collect representative data on blood pressure in children aged 3 to 17 years, in order to create an epidemiological basis for a comprehensive analysis of blood pressure in children and adolescents in Germany. Two oscillometric blood pressure measurements were obtained using an automated device (Datascope Accutorr Plus) and two readings of systolic, diastolic and mean arterial pressure and of heart rate were obtained in a standardised fashion in 14.730 children (7203 girls and 7527 boys). The main aim of this article is a detailed description of the blood pressure measurement in KiGGS, which is important for the interpretation of our findings compared to other studies. Our initial results on the distribution of systolic and diastolic blood pressure confirm previous findings of increasing blood pressure with age and height and of higher systolic blood pressure levels among boys compared with girls from the age of 14 years.