The development of baroreflex sensitivity (BRS in ms/mmHg, BRSf in Hz/mmHg) in 230 children and its relationship to the body growth parameters was studied. In 5 age groups (between 11 and 15 years), all body parameters, systolic blood pressure (SBP), and mean pulse intervals (PI) increased significantly with age. BRSf decreased significantly with age. BRS did not correlate with age, but it correlated positively with weight, height and with PI for the whole group and also for subgroups related to age. This regression line was shifted to the longer PI corresponding to the same BRS. It seems that the tonic and reflex autonomic control of the heart is at least partially independent of each other.