Brugada syndrome is one of the major causes of sudden death among male younger population in Southeast Asian countries including Thailand1. The syndrome manifestation occurs most frequently at night time1. It has been reported that a number of predisposing factors such as exercise, glucose, insulin or meal could modulate the syndrome2-3. In addition, previous studies suggested that an abnormality of autonomic modulation may be related to the syndrome4-5. However, there is no report regarding autonomic response to these factors. Objective of this study was to assess and compare responses of autonomic nervous system to exercise after the ingestion of high glycaemic index (HGI) meal between Thai Brugada syndrome survivors and age-match healthy subjects. Fifteen patients (age between 40 and 60 years) were randomly assigned to perform exercise on electromagnetic cycle ergometer with and without pre-exercise (an hour) ingestion of 97 g of glutinous rice as a HGI meal. Fifteen age-match healthy subjects also underwent the same protocol. After overnight fasting, an hour before and immediately after the exercise blood samples were collected to analyze glucose and insulin concentrations. Electrocardiogram was recorded and analyzed for heart rate variability (HRV) and heart rate recovery (HRR) throughout the experiment. Data were compared by paired and unpaired-t test and presented in mean ± SE. Our procedure was approved by ethic committee of Khon Kaen University under the Declaration of Helsinki in 1964. The results revealed that blood glucose (Brugada = 87.67 ± 1.53 and 108.67 ± 5.62 mg/dL and healthy = 93.33 ± 3.70 and 110.93 ± 7.20 mg/dL) and insulin concentration (Brugada = 16.52 ± 3.10 and 25.28 ± 3.00 uIU/ml and healthy = 9.98 ± 1.43 and 24.35 ± 4.46 uIU/ml) significantly increased (p<0.05) in both groups with HGI meal. Meanwhile blood parameters were not significantly different between groups without HGI meal. Having HGI meal did not affect HRR (Brugada with- and without HGI = 22 ± 2, 24 ± 2 beats and healthy = 27 ± 3, 24 ± 3 beats). In addition, both groups did not show any difference in resting HRV. However, Brugada survivor showed a significantly lower sympathetic activity (p<0.05) indicated by LF(nu) after exercise without HGI diet. LF(nu) with and without HGI diet during a final stage of exercise testing of Brugada and control were 42.88 ± 6.65, 30.23 ± 5.67 nu and 51.56 ± 3.60, 47.77 ± 3.54 nu, at 1 min of HRR were 47.64 ± 5.83, 34.75 ± 4.32 nu and 44.25 ± 4.01, 49.87 ± 4.40 nu and cool down periods were 43.78 ± 5.92, 32.64 ± 4.59 and 47.24 ± 3.86, 45.51 ± 4.13 nu. Our results suggest that HGI meal stimulated insulin secretion and sympathetic nervous activity in Brugada syndrome survivors whereas without any effect on healthy subjects.