The complexity of the cardiovascular function is related to a wide interindividual variability (VA) that changes with age. The aim of our study was to investigate the spontaneous blood pressure (BP) VA in 3 groups of 20 healthy subjects (S) each, 10 M and 10 F: Group I newborns 24 hours old; Group II 30-40 yrs; Group III 70-80 yrs. Each S underwent BP monitoring in a comfortable condition for 15'. Our data show an increase, with age, of both the average systolic and diastolic BP, paralleled by a simultaneous decrease of their standard deviations. Furthermore, the three distributions show a reasonably gaussian behaviour (maximum absolute value of the skewness was 0.21). These results emphasize the age-dependent reduction in functional flexibility of the cardiovascular system. A major pool of subjects is required to confirm our preliminary data.