As part of a programme designed to determine precursors of arterial hypertension and atherosclerosis in children and adolescents, a cross-sectional study involving the groups of families whose children had different baseline arterial pressure levels was conducted. An association between the level of arterial pressure in the children and the blood pressure levels and prevalence of cardiovascular diseases in their first-degree relatives was found. The most informative signs for decreased and increased arterial blood pressure levels in children were identified. The findings should be taken into account when selecting groups of children who require close medical surveillance.