Adolescent and young adults’ (AYAs’) involvement in advance care planning and end-of-life discussions may enhance the decision-making process, reduce stress, and improve the patient’s quality of life. Given the importance of establishing adequate communication and having culturally appropriate tools to introduce advance care planning, our article describes the cross-cultural adaptation of the advance care planning guide, Voicing My CHOiCES™, in Australia and in Brazil. In Brazil, the process involved initially translating the document to Portuguese followed by evaluation by a group of providers and patients (aged 18–39) undergoing cancer treatment. The document was revised based on the feedback received, then back-translated to English and discussed with Voicing My CHOiCES authors to refine the final version in Portuguese. In Australia, a multiperspective interview-based study was undertaken with AYA cancer patients/survivors (aged 15–25), siblings, parents, and a range of health care providers from the oncology setting to determine the perceived acceptability of the tool within the Australian clinical context. These interviews pointed to a variety of recommended adaptations ranging from the aesthetic and linguistic, through to the restructuring of content within the tool. Adaptations for the Australian setting were then revised in an iterative capacity within several focus groups of AYA participants and health care providers. The processes used in both countries highlight ways to engage youth living with a life-limiting illness in conversations about advance care planning and how to develop culturally appropriate clinical tools. (PsycINFO Database Record (c) 2018 APA, all rights reserved)