Various types of health functional foods (HFF) are popularly used among middle-aged. We surveyed 946 middle-aged in Korea for HFF use and significant variables for their HFF use including demographic characteristics, health related variables and nutritional beliefs. The use prevalence of HFF was 58.9%, and among all types of HFF, red ginseng products were taken most frequently, followed by nutritional supplements, ginseng products > mushroom products. HFF was taken more frequently in subjects from high monthly family income (p < .001), and in those from families with a high socioeconomic status (p < .001) in comparison to each corresponding group. Mean age of users was higher than nonusers (p < .001). Self concern about health (p < .001) and usage ratio of HFF by family (p < .001) were higher in users than in nonusers of HFF. Total dietary assessment score was not different in two groups, and users had a more positive view concerning the potential health benefit of HFF than nonusers (p < .001). Most users of HFF took HFF when they were healthy (52.8%) and experienced a little effect through the HFF use (51.2%). Most users of HFF obtained the information on HFF through family and relatives (30.5%) and most of them purchased HFF at pharmacy or oriental medicine clinics (44.5%). HFF users preferred multivitamin and Ca-supplements most among the vitamin mineral supplements belonged to HFF. Given the widespread use of HFF and inappropriate usage of HFF among subjects, the proper use of these products for the contribution to their optimal nutrition and overall health is a subject that should be formed through practical nutrition education considering the various variables affecting their HFF use.