Few studies have focused on the relationship between blood pressure in young adults and long-term mortality. Guidelines for hypertension screening and treatment have been based mainly on findings for middle-aged and older populations. This study assessed the relationship of blood pressure (BP) to long-term (25-year) mortality resulting from coronary heart disease (CHD), cardiovascular diseases (CVD), and all causes. The cohort consisted of 10 874 men aged 18 to 39 years at baseline. Using the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure classification for systolic and diastolic BP, men with high-normal BP and stage 1 hypertension had a higher risk of death and a shorter life expectancy. Above-normal BP is significantly related to increased long-term mortality resulting from CHD, CVD, and other causes in young men. The study underscores the need for prevention, early detection, and control of high BP levels starting in young adulthood.