Aim To explore the correlation between brachial-ankle pulse wave velocity (BaPWV) and early renal damage in young and middle-aged patients with essential hypertension and its diagnostic value. Methods A retrospective study was conducted on 317 young and middle-aged patients with essential hypertension. The glomerular filtration rate (eGFR) was estimated by the chronic kidney disease epidemic cooperation equation (CKD-EPI). Hypertensive patients were divided into two groups:111 patients with abnormal renal function (eGFR<90 mL/(min·1.73 m²)) and 206 patients with normal renal function (eGFR＞90 mL/(min·1.73 m²)). The BaPWV, blood lipid combination, serum creatinine, urea nitrogen, fasting blood glucose, urinary microalbumin, cystatin C and homocysteine were detected and compared between the two groups. The eGFR <90 mL/(min·1.73 m²) was used as the criterion to diagnose early renal damage. The sensitivity and specificity of BaPWV in diagnosing early renal damage in young and middle-aged patients with essential hypertension were evaluated by ROC curve. Results ①The BaPWV, systolic blood pressure, serum creatinine, urea nitrogen, cystatin C and homocysteine in patients with abnormal renal function were higher than those in patients with normal renal function (P＜0.05). ②Pearson correlation analysis showed that BaPWV was negatively correlated with eGFR in young and middle-aged patients with essential hypertension (r=－0.339, P＜0.05). After adjusting for homocysteine, urinary microalbumin, systolic blood pressure, diastolic blood pressure and cystatin C, BaPWV was still an independent risk factor for early renal damage in patients with essential hypertension (OR=0.8,5%CI:0.997～0.999, P<0.05). ③ROC curve showed that the area under the curve of BaPWV was 0.676 (95%CI:0.616～0.736).When BaPWV was taken 1 479.5 cm/s, the diagnostic efficiency was the highest, the sensitivity was 76.7%, and the specificity was 56.3%. Conclusions BaPWV is associated with early renal impairment in young and middle-aged patients with essential hypertension, and BaPWV has certain significance in the diagnosis of early renal impairment in young and middle-aged patients with essential hypertension. BaPWV>1 479.5 cm/s can be used as a sensitive index in the diagnosis of early renal impairment in young and middle-aged patients with essential hypertension.