Purpose <p>This study aimed to explore the treatment decision-making experiences of older patients with cancer, their family caregivers, and healthcare providers.</p> Methods <p>A qualitative study was conducted using focus group interviews at a tertiary hospital in South Korea. The groups were divided into patients with cancer (aged 75 and older), family caregivers, and healthcare providers. Eight patients, 11 caregivers, and 10 healthcare providers participated in the study. The interviews were transcribed and thematically analyzed to identify key themes across the three groups.</p> Results <p>Patients, family caregivers, and healthcare providers shared interrelated yet distinct perspectives on treatment decisions for older adults with cancer. Patients wanted to maintain life and quality of life but felt anxious about side effects and often deferred decisions to physicians or family. Caregivers sought to reduce suffering and protect dignity by gathering information and relying on the guidance of physicians. Healthcare providers focused on safety and shared decisions, considering preferences, prognosis, and function, but faced challenges due to time limits and the lack of age-specific guidelines.</p> Conclusion <p>This study highlight the complex nature of treatment decisions for older adults with cancer, shaped by emotional, relational, and clinical influences across patients, families, and clinicians. Findings emphasize the need for personalized, ethically sensitive approaches that respect the unique values of this population. Improving decision-making in geriatric oncology requires better interdisciplinary coordination, age-specific protocols, and practical support for caregivers. Tailored decision aids can help older adults make informed, value-aligned choices that reflect both medical needs and personal priorities.</p>