This study aimed to investigate advance care planning needs expressed online. This study collected data from online community posts and healthcare news sites. The search keywords included "death," "euthanasia," "life-sustaining medical care," "life-sustaining treatment," "advance directives," "advance medical directives," and "advance care planning." Data collection spanned from February 2018 to February 14, 2020. Out of 2,288 posts, 1,190 were included in the final analysis. Data analysis was conducted using NVivo 12, a qualitative data analysis software program. Content analysis categorized patients' advance care planning needs into eight themes, 11 theme clusters, and 33 meaningful statements. Similarly, care providers' advance care planning needs were categorized into eight themes, 14 theme clusters, and 42 meaningful statements. The identified themes of care needs included life-sustaining medical care, decision-making related to life-sustaining medical care, physical care, environmental care, supportive and spiritual care, respect, preparing for death, and family. This study identified care needs from the perspectives of patients and their families. The findings may serve as preliminary data for future research and clinical applications.