OBJECTIVES: To understand sleep quality, oxidative stress levels, and heart rate variability (HRV) in subjects with hypertension. This study aims to create baseline data in hypertensive subjects to research the possibility of further estimating the risk of developing cardiovascular mortality and morbidity in a patient with hypertension. DESIGN AND METHODS: This analytical cross-sectional study, encompassing 128 study subjects of both genders, with 64 hypertensive subjects, analyse the co-relation of sleep quality, malondialdehyde, and heart rate variability in hypertensive and normotensive subjects. The study was done in a tertiary teaching institute in northern India for 14 months. Descriptive statistics were used, and the independent t-test, Mann-Whitney U test, and Chi-square were used to find the association among the variables. Linear regression was used to estimate the effect of blood pressure on malondialdehyde levels. RESULTS: Subjects with hypertension were found to have poor sleep quality (Global PSQI score >/=5, p=0.0001) and an increased malondialdehyde level (0.30303+/-0.17193 microM/L, p=0.0001). The hypertensive subjects were found to have lower parasympathetic activity as indicated by low high frequency (2.79463+/-473.220280; p=0.0001) and increased sympathetic activity; low frequency/high frequency (2.29823+/-2.792441; p=0.0001). Multivariate linear regression predicts that with one unit increase in systolic blood pressure, the malondialdehyde level increases by 0.006 units (p=0.002; 95% CI). CONCLUSION: Among the hypertensive group, there is significantly increased oxidative stress level, poor quality of sleep, and increased sympathetic activity, thereby predisposing the subjects to increased risk of cardiac morbidity and mortality.