Background: In 2019, the Patient Autonomy Act went into effect, allowing Taiwanese citizens to establish legal advance decisions. In an effort to secure a more realistic and accurate perception of situations, a virtual reality video was developed by the palliative care team of Chi-Mei hospital in southern Taiwan for citizens to use before advance care planning. This study explores the change in participants’ preference and certainty regarding end-of-life decisions after using this tool. Methods: Participants were at least 20 years old and capable of reading and understanding the information provided in the written handout with information about the legal process of making an advance decision. They completed pre-test questionnaires, viewed a six-minute 360-degree virtual reality video on a portable headset and then completed a post-test questionnaire about their preference on the 5 medical options including CPR, life-sustaining treatments, antibiotics, blood transfusion, and artificial nutrition and hydration, followed by feedback on the helpfulness of the virtual reality. The control group included 40 participants who only read the handout and they also completed pre-test and post-test questionnaires. Results: After viewing the virtual reality video, preference for refusing CPR, life-sustaining treatment, antibiotics, blood transfusion, and artificial nutrition and hydration increased significantly in the virtual reality intervention group. Uncertainty regarding the 5 medical options mentioned above are significantly decreasing. The intervention was generally recognized by participants for its help of making decision. Discussion: The decrease in the number of participants who could not make decisions indicate that the virtual reality video may be helpful for users in making end-of-life decision. According to feedback, the virtual reality video helped equip users with better understanding of medical scenarios, and it is a good decision aid for advance care planning. Conclusion: This is the first study since the Patient Autonomy Act has been passed that explores the effectiveness of using a virtual reality video as a decision aid in advance care planning and reveals decreased preference of CPR, life sustaining treatment, antibiotics, blood transfusion and artificial nutrition and hydration after intervention. This decision aid proved to be an effective tool for clarifying their end-of-life care preferences.