Children with brain tumors experience significant alterations to their health and well-being due to the tumors themselves and oncologic treatment. Caring for children with brain tumors can have significant impacts on families, especially during and shortly after treatment. In this study of the impacts on families caring for children undergoing proton radiation therapy for brain tumors, the authors found that families experienced a broad array of negative impacts. Families reported feeling like they were living on a roller coaster, feeling that others treated them differently, and having to give up things as a family. In the multivariable linear regression model, older age of the child and higher reported child health-related quality of life were associated with less family impact. The presence of concurrent chemotherapy was associated with increased family impact. This is the first study to specifically evaluate the families of children being treated with proton radiation therapy. The findings in this study are consistent with the findings in other studies of children treated with standard therapy that show that families experience a variety of stressors and negative impacts while their children are receiving treatment. Health care providers should be aware of the potential impacts on families of children with brain tumors and their treatment to provide robust services to meet the health, psychological, and social needs of such children and their families.