Hypertension is a major risk factor for cardiovascular events and the goal of treating hypertension is to prevent complications due to these events. However, some other properties, including few side-effects and improvement of the quality of life (QOL), are desirable in a drug as well as its antihypertensive effect. Dehydropydine calcium-channel blockers (DCCBs) are the most frequently used antihypertensive agents in Japan. The antihypertensive effect of DCCBs is satisfactory, but side-effects, e.g. nocturia, flushing and palpitations, are a problem. The aim was to evaluate the effects of a change of treatment from DCCBs on the QOL of hypertensive patients. An open study was performed to evaluate the effects of switching treatment from DCCBs to angiotensin II receptor blocker (ARB) therapy on the QOL of hypertensive patients. The ARBs have been reported to be effective and well-tolerated antihypertensive drugs. Candesartan cilexetil was selected because it is the most frequently used ARB in Japan. One hundred patients with mild to moderate hypertension, being treated with DCCBs, were randomly selected to receive candesartan cilexetil (8-12 mg once a day). The patients were followed for 3 months, while blood pressure (BP), side-effects and QOL were monitored. BP was equally well controlled before and after the change of antihypertensive therapy. The candesartan cilexetil-treated patients exhibited improvement of several aspects of QOL, including general symptoms, physical symptoms and well-being, work and satisfaction and sleep scale. Emotional state and cognitive function also improved. Patients aged 65 years or younger achieved significant improvement of sexual function. Changing treatment from DCCBs to ARB therapy achieved equal BP control with a lower drug dose. Moreover, the change to cadesartan cilexetil had a positive impact on the QOL.