Background: The aim of radiotherapy is to provide a cure and/or symptomatic relief for children with cancer. Treatment is delivered on a daily basis, 5 days per week, over the course of 5 to 35 days. Many parents find that leaving their children alone during treatment and exposing them to radiation is a challenging experience. To gain an understanding of parents’ lived experiences, 10 parents were asked to keep a diary while their children underwent radiotherapy. Methods: A descriptive inductive design with a hermeneutic-phenomenological approach was chosen to analyze the diaries. The parents were asked to write down their lived experiences while their children underwent radiotherapy. Daily notes, both short and long, were desirable. Findings: The parents described radiotherapy as a balancing act involving a constant attempt to maintain a balance between coercing and protecting their children in order to improve their children’s chances of survival. Meanwhile, the parents themselves were struggling with their own despair and feelings of powerlessness. While protecting their children, they experienced a sense of hope and felt that they had gained control. Conclusion: Parents’ daily written reflections are important for clinical practice and provide vital knowledge. Parents need support when focusing on coercing and protecting their children and help with information and routines that enable them gain control.