Objective: To analyze the difference between women under and over 75 years of age, in relation to multidimensional frailty and quality of life, controlling for variables determining the life course, health aspects, comprehensive geriatric assessment and comorbidity. Methodology: Descriptive, analytical and cross-sectional study in 356 elderly women treated at the family health centers of the Pintana and Puente Alto communes in Santiago de Chile. Data collection was performed by previously trained research assistants. The following data were collected: life course determinants, health aspects, comprehensive geriatric assessment, comorbidity, multidimensional frailty, and quality of life. The data analysis was descriptive, correlational and linear regression. Results: Being over 75 years of age implies that, at 95% confidence, there is a quality of life 17.09 points higher in relation to adult women under 75 years of age. Conclusions: The multidimensional fragility, physically, affects women under 75 years of age in feeling physically healthy, while the social influences women over 75 years of age and the psychological in both groups. On the other hand, the quality of life has a positive impact on women over 75 years of age.