Purpose: Family caregivers play a significant role in the care of cancer patients, especially in their end of life. Identifying and meeting the needs of these caregivers is essential to improving their quality of patient care. This study was conducted to identify the unmet needs of the caregivers of end-of-life cancer patients. Methods: A total of 18 semi-structured interviews were held with the family caregivers of end-of-life cancer patients using purposive sampling. The interviews were recorded, transcribed, and analyzed using qualitative content analysis. Results: The analysis of the data led to the formation of three main categories, including social needs, cognitive needs, and psychological needs. The social needs category comprised of the subcategories of support for care, effective communication and financial support. The cognitive needs category comprised of educational support and support in decision-making. The psychological needs category comprised of support for psychological trauma, preparation to confront the reality of the death of a loved one, and support for mourning. Conclusions: The family caregivers of end-of-life cancer patients take on the responsibility of many aspects of care for their patient, but many of their own needs remain unmet. The findings of this study can be used for healthcare policy planning and the development of palliative interventions, particularly for the family caregivers of end-of-life cancer patients.