The purpose of this study was to use an aging anxiety scale for Korean middle-aged adults to determine whether existing known factors could affect their aging anxiety and to see how the pattern of the aging anxiety in Korean middle-aged might vary depending on gender. An online survey was conducted with the middle-aged aging anxiety scale, the aging knowledge scale, the elderly contact experience scale, the age stereotypes scale, and the death anxiety scale for 246 middle-aged men and women aged 40 to 59 years. As a result of the analysis, based on the total aging anxiety score, aging anxiety of women was significantly higher than that of men. In addition, it was found that women's aging anxiety was significantly higher than men's for the following sub-factors of aging anxiety: 'loss of economic power', 'loss of physical health', and 'loss of attractiveness'. In addition, gender, perceived health conditions, and death anxiety significantly predicted aging anxiety. However, knowledge of aging, experience of contact with the elderly (frequency and quality), and stereotypes of the elderly did not affect aging anxiety. Based on these results, clinical implications, limitations, and suggestions for further research were discussed.