Background: Adolescents and young adults (AYAs) with advanced cancer often receive intensive end-of-life care, yet it is unclear if this is goal-concordant. Advance care planning (ACP) video tools may promote identification and communication of AYA preferences. Patients and Methods: We conducted a dual-site, 1:1 pilot randomized controlled trial of a novel video-based ACP tool in 50 dyads of AYA patients aged 18 to 39 years with advanced cancer and their caregivers. ACP readiness and knowledge, preferences for future care, and decisional conflict were obtained pre, post, and 3 months after the intervention and compared between groups. Results: Of the 50 AYA/caregiver dyads enrolled, 25 (50%) were randomized to the intervention. Participants primarily identified as female, white, and non-Hispanic. Most AYAs (76%) and caregivers (86%) identified their overall goal as life-prolonging preintervention; less identified this goal postintervention (42% AYAs; 52% caregivers). There was no signi