Objective: Data were retrieved from the Korean National Health and Nutrition Examination Surveys (V-VII). Participants aged 20-39 years without history of hypertension or systolic BP (SBP) and diastolic BP (DBP) less than 140/90mmHg were included (N=8,180). Study subjects were categorized into normal BP (SBP <120 and DBP <80mmHg), elevated BP (SBP 120-129 and DBP <80mmHg) and stage 1 hypertension (SBP 130-139 or DBP 80-89mmHg). Study endpoint was kidney injury defined as eGFR <60mL/min/1.73m2 or presence of proteinuria by dipstick urine test. Methods: The mean age of study subjects was 30.2 years and 45.3% were male. The mean SBP and DBP levels were 115.3/76.7 and 105.2/70.1mmHg in male and female subjects. The prevalence of kidney injury was 12.6% among study subjects and higher in the high BP category groups in both male and female. In multivariable logistic regression analysis for the risk of kidney injury, stage 1 hypertension group was associated with higher risk of kidney injury in both male and female (OR, 1.27; 95% CI, 1.04-1.61 and OR, 1.55; 95% CI, 1.19-2.01, normal BP as reference group). Results: This study showed stage 1 hypertension is associated with increased risk of kidney injury in young adults without history of hypertension. These results suggest young adults to control BP under 130/80 mmHg to prevent future kidney disease development. Conclusions: Objective: Elevated blood pressure (BP) is well-known risk factor for chronic kidney disease. However, the association between elevated BP and kidney injury is not well investigated in young adults. This study aimed to evaluate the association between BP categories based on 2017 American College of Cardiology/American Heart Association BP guideline and the risk of kidney injury among Korean young adults without history of hypertension. Methods: Data were retrieved from the Korean National Health and Nutrition Examination Surveys (V-VII). Participants aged 20-39 years without history of hypertension or systolic BP (SBP) and diastolic BP (DBP) less than 140/90mmHg were included (N=8,180). Study subjects were categorized into normal BP (SBP <120 and DBP <80mmHg), elevated BP (SBP 120-129 and DBP <80mmHg) and stage 1 hypertension (SBP 130-139 or DBP 80-89mmHg). Study endpoint was kidney injury defined as eGFR <60mL/min/1.73m2 or presence of proteinuria by dipstick urine test. Results: The mean age of study subjects was 30.2 years and 45.3% were male. The mean SBP and DBP levels were 115.3/76.7 and 105.2/70.1mmHg in male and female subjects. The prevalence of kidney injury was 12.6% among study subjects and higher in the high BP category groups in both male and female. In multivariable logistic regression analysis for the risk of kidney injury, stage 1 hypertension group was associated with higher risk of kidney injury in both male and female (OR, 1.27; 95% CI, 1.04-1.61 and OR, 1.55; 95% CI, 1.19-2.01, normal BP as reference group). Conclusions: This study showed stage 1 hypertension is associated with increased risk of kidney injury in young adults without history of hypertension. These results suggest young adults to control BP under 130/80 mmHg to prevent future kidney disease development.