Left ventricular (LV) hypertrophy is related to blood pressure level and neurohormonal factors. The authors previously demonstrated that arterial norepinephrine levels predict LV mass in middle-aged men who developed hypertension through 20 years. The aim of this 20-year prospective study was to investigate arterial vasopressin, aldosterone, and renin as long-term predictors of LV mass. Normotensives (n=17), subjects who developed hypertension (n=17), and sustained hypertensives (n=22) were compared at baseline (42 years) and at follow-up (62 years). There were no significant differences in baseline vasopressin, aldosterone, or renin levels. The group with sustained hypertension had more LV hypertrophy (P=.025) at follow-up. Among new hypertensives, multiple regression analysis demonstrated that baseline arterial vasopressin (β-0.53; P=.041) and aldosterone (β-0.56;P=.032) independently explained LV mass index (R2=0.85; P=.035). In conclusion, baseline arterial vasopressin and aldosterone, but not renin, appear to predict LV mass in middle-aged men who developed hypertension over a 20-year period.