The presence of cancer and additional parental responsibilities can increase strain for individual patients as well as for their children. The construct of health-related quality of life (HRQL) is appropriate to measure a combination of physical, mental and social consequences as a result of disease. However, previous research has merely focused on symptom checklists. This study addresses the following questions: (i) does HRQL in children and their parents with cancer differ compared to the general population? (ii) Are there any variables that are associated with HRQL in children? (iii) What are current psychosocial support needs? A population-based survey of 976 survivors (<6 years post diagnosis) with minor children between 6 and 18 years (n = 1,449) was conducted with two German cancer registries. HRQL was assessed using SF-8 (survivors) and Kidscreen (children). The results were compared to normative populations, and predictors associated with HRQL in children were evaluated within a multilevel model. We found that the HRQL in children was better compared to the norm. Only children with support needs had worse HRQL. Older age, having a mother with cancer, having a parent not living together with a partner, and worse parental physical and mental health influenced HRQL in children. Illness characteristics were irrelevant. Even with a mean of 3.5 years after diagnosis, survivors had lower physical and mental health compared to the norm. Our findings reinforce the need for health professionals to pay attention to younger patients and their children. Even years after diagnosis, life might not have returned to normal.