"bstract Background: Ageism has been described as a form of prejudice of one age group against another and is experienced in a range of ways. Little is known about the impact of ageism on the health and well-being of older women. Interacting within the healthcare system becomes more complex with age. This occurs because of increased comorbidity and changing perceptions of the ageing body. Objectives: This study aimed to explore the concept of ageism by reviewing older women’s perceptions and experiences of accessing breast cancer screening. Design: Drawing on data gathered by the same researchers, this study utilises a secondary qualitative analysis of primary data. Methods: This study draws on a purposive sample of 60 women aged ⩾75 years who participated in an Australiawide study conducted in 2022. In-depth individual interviews were audio-recorded, transcribed verbatim and imported into NVivo software (Version 15) to enable thematic analysis. Secondary analysis drew on a theoretical lens of ageing together with researcher reflection of ageism in society. Results: Women in the study reported experiencing changes in their interaction with and perceptions of healthcare based on age. Perceptions of ageism were grouped into theoretical themes relating to micro, meso and macro concepts of ageism. Thematic headings included: ageing with self-determination and autonomy; meeting the changing health needs of older women and the invisible generation. Generational differences, health system experiences, societal influences and use of technology and online platforms were discussed. Results indicate that ageism may be based on both perception and experience. The impact on health and well-being of women aged ⩾75years was variable and often modified by associated peer groups. Conclusion: Identifying and describing the multiple layers of ageism presents healthcare providers with an opportunity to understand how ageism is experienced by older women. This has implications for effective communication and care. Health messages designed to reach older women must be cognizant of both implicit and explicit forms of ageism. Establishing trust and avoiding reliance on online platforms as sources of information are important for this age group. Health promotion and prevention initiatives based on age-related criteria may contribute to notions of ageism."