Previous studies have shown that psychological well being is associated with reduced risk of cardiovascular disease, but whether well being might be specifically associated with reduced risk of hypertension has not been rigorously investigated in prospective studies. This study examined the prospective association between two measures of psychological well being and incident hypertension. Psychological well being (emotional vitality and optimism) and cardiovascular risk factors (demographics, health status, health behaviors, psychological ill being) were assessed at baseline between 1991 and 1994, and approximately every 3 years following through 2002-2004. High emotional vitality was associated with reduced hypertension risk, and favorable health behaviors only explained part of the relationship. Optimism was not significantly associated with hypertension.