Family factors, such as household income and parental psychosocial distress, have been associated with quality of life in children with cancer. However, relationships between parent anxiety and child health-related quality of life (HRQoL) have not been evaluated in children with advanced cancer. To examine relationships between parent anxiety and both parent-reported and child self-reported HRQoL for children with advanced cancer. Children (aged 5-17 years) with relapsed or refractory cancer and their parents participated in this single-institution cross-sectional study. Parents completed measures of their own baseline anxiety (State-Trait Anxiety Inventory-Trait [STAI-T] form) and their ill child's HRQoL (PedsQL Generic and PedsQL Cancer, parent report). Children completed age-specific PedsQL Generic and PedsQL Cancer, child report. Spearman's rho coefficients assessed correlations between total parent STAI-T score and both parent-reported and child-reported HRQoL scales. Twenty children ( = 9.5 years, 50% female) and their 20 parents (90% mothers) participated. The strongest and statistically significant ( < .05) correlations were inverse associations between parental trait anxiety and parent-reported child psychosocial HRQoL ( = -.54), emotional functioning ( = -.49), school functioning ( = -.45), and child pain and hurt ( = -.45). Correlations of parental anxiety with all dimensions of child-reported HRQoL were generally smaller ( < .40), positive, and not statistically significant ( > .05). Given the inverse correlations between parental anxiety and child psychosocial HRQoL, assessment of parent mental health needs and access to interventions should be provided routinely for parents of children with advanced cancer.