Objectives: This study intended to determine significant factors that influence the health-related quality of life ("HRQoL"; EuroQol 5 Dimension health-related quality of life (EQ_5D) & EuroQol visual analogue scale (EQ_VAS)) of the elderly in Korea. Methods: This study was based on 3,903 subjects aged 65 years or more who participated in the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V), 2010~2012. The HRQoL was analyzed by various factors (general characteristics, health habits, mental health, chronic diseases, nutrient intakes). SPSS statistics for complex samples (Windows ver. 21.0) was used. Results: The HRQoL was higher in the males, those with higher educational level or higher income level while it was lower in those belong to single households. In particular, the EQ_5D was significantly higher in the group who reported walking practice, moderate physical activity (male), and the group who reported no vigorous physical activity (female). The EQ_VAS was significantly higher in the group who reported walking practice. Both EQ_5D and EQ_VAS were significantly lower in the group with stress, melancholy, suicidal thinking, and osteoarthritis. EQ_5D was significantly lower in the group with < 75% Estimated Energy Requirements (EER) in energy intake, and with < Estimated Average Requirements (EAR) in iron or niacin intake. A stepwise regression analysis revealed that i) higher educational level (male), and good self-rated health status significantly increased the EQ_5D, ii) age, alcohol intake (male), melancholy (female), suicidal thinking, osteoarthritis, and niacin intake deficiency (male) significantly decreased the EQ_5D, iii) higher income level (male) and good self-rated health status significantly increased the EQ_VAS, and iv) age (male), stress, suicidal thinking (female) and osteoarthritis significantly decreased the EQ_VAS. Conclusions: This study suggested that general characteristics, mental health, osteoarthritis, and niacin intake were associated with the HRQoL. Prospective research of long-term control is needed to establish the causal relationship between factors and the HRQoL.