In the literature, one can find a common opinion that 1-3% of the children population suffers from arterial hypertension. This rate depends on the diagnostic criterion and the studied population (age, sex, race etc.). The aim of this work was to present a rather large group (271 patients) treated for hypertension in our centre between 1993-2000. The ranged children from newborns to 18 year olds (mean = 13.75 +/- 4.5 years). In the study period, there is approximately a four fold annual increase in the number of hypertensive patients among all patients of the pediatric cardiology units. On the basis of our material, the rate of arterial hypertension depends on the age of the pediatric patients with as many as 3/4 of the children being teenagers > or = 14 years old. In the teenager group, all cases of essential hypertension were observed. Almost 70% of the studied children were boys. In about half the studied group, hypertensive changes on the eye fundus were found. One can suspect that automatic 24-hour measurement of arterial hypertension (so called "tension Holter") is of great value in children. A number of individual measurements exceeding the norm during "tension Holter" correlated with eye fundus vessel changes. In conclusion more attention should be paid to arterial hypertension in children. For example, in our previous paper published in 2000 it was stated that among 2.3% of "healthy" school children who suffered from arterial hypertension, non of these children were suspected of suffering from arterial hypertension.