Simple SummaryInformal caregivers are an underrepresented group in the AYA literature, as attention is often paid to the patients’ wishes and needs. Caring for young cancer patients brings age-specific challenges, which are related to the life-phase of the patients. This causes these caregivers to differ from those caring for children and older patients. This review aimed to provide an overview of the impact of being a caregiver for an AYA cancer patient on different domains of their lives, as well as to report the unmet needs they identify. By being more attentive to the caregivers and their needs, and intervening accordingly (e.g., via social support or psychological interventions), caregivers’ quality of life can increase, which allows for better caregiving capabilities. This not only has a positive impact on the patient, but might also lead to a decreased caregiver burden.AbstractAYAs with cancer (aged 15 to 39 at primary diagnosis) form a specific group within oncology, and there is limited information on the impact on their informal caregivers. This scoping review aimed to gain insight into the burden on caregivers of AYAs with cancer and identify the unmet needs they might have. Eligible articles focused on impacts in one of the domains of caregiver burden (physical, psychological, social, on schedule, financial) or unmet needs. In all domains of caregiver burden, impact was reported by caregivers. Caregiving leads to physical problems (such as sleep problems) and psychological symptoms (e.g., depression, anxiety, and negative emotions). Loneliness is reported, and little peer-support. Many different tasks and roles must be undertaken, which is perceived as challenging. In addition, there is a financial impact and there are unmet needs to be met. Several domains of the lives of caregivers of AYA cancer patients are negatively affected by the disease. Some of these are age-specific, and tailored to a particular group of caregivers (parents, partners, or friends). AYA cancer patients represent a wide age range, resulting in the engagement of many different caregivers. Future research will need to take this into account in order to adequately provide support.