OBJECTIVES: For children, adolescents, and young adults with complex chronic conditions advance care planning may be a vital component of optimal care. Advance care planning outcomes research has previously focused on seriously ill adults and adolescents with cancer where it is correlated with high-quality end-of-life care. The impact of advance care planning on end-of-life outcomes for children, adolescents, and young adults with complex chronic conditions is unknown, thus we sought to evaluate parental preferences for advance care planning and to determine whether advance care planning and assessment of specific family considerations during advance care planning were associated with differences in parent-reported end-of-life outcomes. DESIGN: Cross-sectional survey. SETTING: Large, tertiary care children’s hospital. SUBJECTS: Bereaved parents of children, adolescents, and young adults with complex chronic conditions who died between 2006 and 2015. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: One-hundred fourteen parents were enrolled (54% response rate) and all parents reported that advance care planning was important, with a majority (70%) endorsing that discussions should occur early in the illness course. Parents who reported advance care planning (65%) were more likely to be prepared for their child’s last days of life (adjusted odds ratio, 3.78; 95% CI, 1.33-10.77), to have the ability to plan their child’s location of death (adjusted odds ratio, 2.93; 95% CI, 1.06-8.07), and to rate their child’s quality of life during end-of-life as good to excellent (adjusted odds ratio, 3.59; 95% CI, 1.23-10.37). Notably, advance care planning which included specific assessment of family goals was associated with a decrease in reported child suffering at end-of-life (adjusted odds ratio, 0.23; 95% CI, 0.06-0.86) and parental decisional regret (adjusted odds ratio, 0.42; 95% CI, 0.02-0.87). CONCLUSIONS: Parents of children, adolescents, and young adults with complex chronic conditions highly value advance care planning, early in the illness course. Importantly, advance care planning is associated with improved parent-reported end-of-life outcomes for this population including superior quality of life. Further studies should evaluate strategies to ensure high-quality advance care planning including specific assessment of family goals.