Objectives: This study was conducted in order to confirm the moderating effect of gratitude and social support in a relationship between meaning in life and aging anxiety targeting middle-aged women. Methods: For this, a questionnaire survey was carried out targeting 356 middle-aged women from 40 years old to under 60 years old who dwell in the Seoul and Gyeonggi area. After excluding 26 insincere responses, 330 responses were finally applied to the study using hierarchical regression analysis. Results: First, meaning in life and aging anxiety showed a significant negative relationship. Still, it was indicated that a more positive meaning in life leads to a lower aging anxiety level. Second, in the relationship between meaning in life and aging anxiety, gratitude appeared to have a moderating effect. Third, in the relationship between meaning in life and aging anxiety, social support was found not to show a significant moderating effect. Conclusions: Through the results of this study, the influential factors of reducing aging anxiety in middle-aged women can be expected to include meaning in life and gratitude. Also, gratitude was verified to potentially have a moderating effect on a relationship between meaning in life and aging anxiety. Meaning in life and gratitude have a high possibility of changing through an individual's effort and counseling, thereby suggesting that they may be useful psychological mechanisms in decreasing the aging anxiety of middle-aged women.