BACKGROUND: Hypertension has been reported to cause impaired cardiovagal modulation and a wide variety of cognitive loss. However, the link cardiovagal modulation to neurocognitive impairment has not been studied yet. The present study has compared the link cardiovagal modulation to neurocognitive impairment between prehypertension and newly diagnosed hypertension in young adults. METHODS: One hundred forty-seven subjects (42 normotensives, 54 prehypertensives and 51 newly diagnosed hypertensives) aged between 18-44 years were included in this case-control study. The demographic, anthropometric, basal parameters, heart rate variability (HRV), cardiovascular autonomic function tests (CAFTs), event-related potential P300 and biochemical parameters were recorded in all the groups. Association of various parameters with neurocognitive deficit was studied by Pearson correlation analysis and independent contribution of various factors to cognitive deficit was assessed by multiple regression analysis in the study groups. RESULTS: Total power (TP) of HRV, the marker of cardiovagal modulation was reduced in both prehypertensives and hypertensives compared to controls. Among CAFTs, the DeltaDBP(IHG) was increased, and 30:15 ratio and E:I ratio were decreased in both study groups. The latency of P300 (the marker of neurocognition) was significantly prolonged in prehypertensives and hypertensives and P300 latency was significantly associated with reduction in TP in both the groups. HOMA-IR was increased, and total oxidant capacity was decreased in prehypertensives and hypertensives, and both these parameters had independent contribution to P300. CONCLUSION: Prehypertensives had considerable autonomic imbalance, reduced cardiovagal modulation and neurocognitive deficit that were comparable to newly diagnosed hypertensives. Though the causal relationship between cardiovagal modulation and neurocognitive impairment can\'t be established from the findings of the present study, it appears that neurocognitive deficit might have some possible link to the decreased cardiovagal modulation and metabolic derangements in young prehypertensives and hypertensives.