To compare the health-related quality of life (HRQL) for patients with epilepsy and health subjects, we collected the clinical and demographic data and information on health states by using the Taiwan version of World Health Organization quality of life (WHOQOL)-BREF questionnaire in 296 patients (aged 19-73 years) with confirmed active epilepsy visiting the clinic of National Taiwan University Hospital, and 296 age-, gender-, municipal- and education-matched Taiwanese healthy subjects sampled from a national health interview survey. Multiple regression analyses with stepwise selection strategy were conducted to study risk factors for impairment of HRQL. Patients with epilepsy have poorer HRQL than the healthy population in physical, psychological and social domains but not in environment domain (p<0.005). Patients with less than 4 attacks during the previous 1 month had a better score in the availability and quality of health and social care in environment domain than healthy subjects (p<0.05). After controlling other determinants, seizure frequency, and comobid with other diseases are the important factors in predicting HRQL for epilepsy patients. Patients with employment and married had a significantly better HRQL. Effective control of seizure frequency and thoughtful promotion of positive attitudes in community are essential to improve the HRQL of epilepsy patients.