Objective: To describe health-related quality of life (HRQoL), post-traumatic stress and post-traumatic growth of parents of long-term survivors of childhood cancer (CCS) and study associated factors. Methods: Parents of survivors of the Dutch Childhood Cancer Survivor Study LATER cohort below 30 years and diagnosed 1986–2001 were invited to complete the TNO-AZL Questionnaire for Adult's HRQoL (e.g., sleep and aggressive emotions), Self-Rating Scale for Post-traumatic Stress Disorder, Post-traumatic Growth Inventory, and Illness Cognition Questionnaire. HRQoL domain scores were compared to references using Mann-Whitney U tests. Correlations between post-traumatic stress, growth and HRQoL were evaluated. Medical characteristics of their child and illness cognitions were studied as associated factors of HRQOL, post-traumatic stress and growth. p < 0.05 was considered statistically significant. Results: Parents (n = 661 of n = 448 survivors, 56% female, mean time since child's diagnosis: 21.3 [SD: 3.3] years) reported better HRQoL in social functioning and aggressive emotions than references (r =.08–0.17). Mothers additionally reported better HRQoL in pain, daily activities, sexuality, vitality, positive and depressive emotions (r =.07–0.14). Post-traumatic stress was symptomatic in 3%, and associated with worse HRQoL (r = −0.27–0.48). Post-traumatic growth was positively associated to post-traumatic stress and better HRQoL (r = 0.09–0.12). Cancer recurrence was associated to better HRQoL (β = 0.37–0.46). Acceptance illness cognitions were associated to better (β = 0.12–0.25), and helplessness to worse outcomes (β = 0.14–0.38). Conclusions: HRQoL of parents of young adult survivors of CCS is comparable to references or slightly better. Only a small proportion reports symptomatic post-traumatic stress. Improving acceptance and reducing feelings of helplessness may provide treatment targets for parents with psychosocial problems.