Individuals with hypertensive parents (FH+) have greater risk of hypertension than those with normotensive parents (FH-). Whether autonomic control of arterial blood pressure (ABP) is impaired in young normotensive FH+ is unclear. Thus, in 9 FH- and 11 FH+ (18-25 years), we recorded ABP, ECG, respiration, baroreflex sensitivity (BRS) by the sequence method (changes in R-R interval evoked by spontaneous increases and decreases in systolic pressure (SP)), and as change in R-R interval evoked by the fall in SP that occurs on standing from a squat position, at rest, during slow breathing for 5 min at 6 breaths/min, and during mental stress for 3 min (Colour Stroop test). HRV was computed by time- and frequency domain analyses under each condition. Comparisons with and between FH+ and FH- were done by paired and unpaired t-tests respectively. FH- and FH+ had similar mean ABP (mABP: 85±0.8 vs 90±2.7 mmHg) and respiration (16.1±1.2 vs 15.9±0.6 breaths/min) at rest. Mental stress increased ABP, HR, and respiratory frequency in both FH+ and FH-, but the increase in ABP tended to be greater in FH+ (P=0.07). Vagal indices of HRV (RMSSD and pRR50) decreased during mental stress in FH+, but not FH- (RMSSD: 70.3±14.3 to 45.9±8.8*; 67.2±14.8 to 62.2±23.3 respectively, *: P<0.05 within group). Further, Further, BRS was decreased in response to up- and down-sequences in SP during mental stress in FH+, but during down sequences only in FH- (1.2±0.05 to 1.0±0.05* and 1.2±0.05to 0.9±0.05*; 1.2±0.08 to 1.0±0.06 and 1.2±0.08 to 0.9±0.08* respectively). Moreover, BRS during squat to stand, was lower under resting conditions in FH+ than FH- (0.48 vs 0.69†; †: P<0.05 FH+ vs FH-), but BRS during squat to stand following mental stress decreased in FH- only (to 0.37*). On the other hand, slow breathing increased BRS during up-sequences in FH+ (1.2±0.05 to 1.3±0.05*), but not FH- (1.18±0.08 to 1.34±0.08ms/mmHg), and increased RMSSD, in FH+ only (70.3±14.3 to 78.9±13.5*). These results suggest that young, normotensive FH+ tend to show a greater pressor response to mental stress than FH-, which is accompanied by greater depression of BRS and a substantial decrease in the vagal influence over HR. Thus, it seems BRS regulation of ABP via the vagus is disturbed more during mental stress in FH+ than FH-. On the other hand, as BRS during squat to stand is well-maintained following mental stress in FH+ but not FH-, it seems that young FH+ lack central neural depression of the sympathetic component of BRS that occurs during mental stress in FH-. Since slow breathing enhanced the BRS and increased vagal control over HR in FH+, it may be that regular slow breathing may restore vagal-sympathetic regulation of HR and BRS in FH+ and reduce their future risk of hypertension.