Objective: To investigate the correlation between different levels of plasma renin activity (PRA) and left ventricular hypertrophy (LVH) in patients with essential hypertension (EH). Methods: A total of 385 EH patients with LVH were enrolled as study subjects. Based on PRA levels, patients were divided into three groups: the low-renin group (PRA 4.50 ng/mL/h, n=70). General clinical data, echocardiographic parameters, and biochemical indicators were compared between the groups, the relationship between different PRA levels and LVH in EH patients were analyzed by Pearson correlation analysis. Results: The 24-hour mean systolic blood pressure (24hSBP), diastolic blood pressure (24hDBP), and levels of aldosterone and troponin T in the high-renin group were higher than those in the low-renin and normal-renin groups (P<0.05). The high-renin group exhibited the highest values for interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), and left ventricular mass index (LVMI), along with the most impaired left ventricular diastolic function (E peak, E/A ratio) (P<0.05). Pearson correlation analysis revealed that PRA levels were positively correlated with LVMI, IVST, LVPWT, and A peak velocity (P<0.05), and negatively correlated with E peak velocity and E/A ratio (P<0.05). Conclusion: Elevated PRA in EH patients shows a correlation with the severity of LVH and the decline in left ventricular diastolic function, and can serve as an important clinical indicator for assessing the risk of cardiac remodeling in hypertensive patients.