Epidemiological studies indicated that erectile dysfunction (ED) is more frequent and their quality of life (QOL) is deteriorated in patients with essential hypertension as compared with normotensive subjects. Since both ED and hypertension influence QOL, it is not clear which malady has a more serious influence on QOL. We conducted a case control study to investigate incidence and impact of ED on QOL. In 102 patients aged 40 to 59 under treatment for hypertension (Hypertensive group) and in 245 age-matched normal subjects (Control group), QOL and ED were assessed by SF-36 and IIEF5. Criteria for presence of ED is IIEF5 score less than 12. Age adjusted incidence of ED in Hypertension group was higher than that in Control Group (odds ratio 1.7, P < .05). Multivariate logistic regression analysis showed hypertension was related only to a low score in general health, ED was related to low scores in physical, mental health, emotional, vitality, and general health. These data suggest that the influence of ED on QOL is more serious than hypertension in middle age men.