Purpose: This study aimed to investigate factors affecting frailty by age groups among vulnerable elders in Korea. Methods: In this secondary analysis, data were collected from records for 22,868 elders registered in the Visiting Health Management program of Public Health Centers in 2012. Health behaviors, clinically diagnosed disease, frailty, depression and cognitive condition were assessed. Data were analyzed using stepwise regression to determine the associated factors of frailty by age group. Results: Alcohol consumption, physical activity, number of diseases, DM, CVA, arthritis, urinary incontinence, depression and cognitive condition were found to be factors significantly associated with frailty among the elders aged 65~74 (F=135.66, p <.001). Alcohol consumption, physical activity, CVA, arthritis, urinary incontinence, depression and cognitive condition were found to be factors associated with frailty in the elders aged 75~84 (F=245.40, p <.001). Physical activity, CVA, arthritis, depression and cognitive condition were factors associated with frailty in the elders over 85 years of age (F=96.48, p <.001). Conclusion: The findings show that frailty of elders and associated factors were different by age group, and common factors affecting frailty were physical activity, CVA, arthritis, depression and cognitive condition. Thus, these factors should be considered in the development of intervention program for care and prevention of frailty and program should be modified according to age group.