Ventromedial prefrontal cortex (VMPFC) modulates emotional processes and its activation can inhibit cardiovascular sympathetic system in animals. In humans, VMPFC regulates emotional arousal during some behavioural reactions; however, its influence on cardiovascular autonomic system is largely unknown. The aim of the study was to assess cardiovascular autonomic function during positive and negative emotions in healthy persons and in patients with unilateral VMPFC lesions. In 6 patients aged 54.0±7.2 years with left-sided ventromedial prefrontal lesions of the brain (VMPFC-L), 7 patients aged 43.3±11.6 years with right-sided lesions (VMPFC-R) and 13 healthy persons aged 44.7±11.6 years, R-R interval and blood pressure (BP) variability was analysed and the baroreflex sensitivity (BRS) assessed during positive and negative emotional visual stimulation. The control subjects showed a significant R-R interval increase during positive (842.9±32 to 928.8±40 ms) and negative (843.2±31.7 to 1089.0±131.5 ms) emotional stimulation. In VMPFC-L, RRI increased only insignificantly with positive and negative emotions, while in VMPFC-R, there was a significant reduction in RRI (964.0±20.7 to 847.4±43.4 ms) and BRS (13.1±2.1 to 5.6±1.3 ms mmHg-1) and a significant increase in systolic BP (121.0±7.4 to 130.8±6.7 mmHg) during pleasant and a tendency to decreased RRI during unpleasant emotions. T ; hese results are consistent with a role for VMPFC, especially the right VMPFC, in the modulation of cardiovascular autonomic activity associated with emotions via its influence on BRS and an inhibitory effect on heart rate and BP.