This study was conducted to examine the role of video education on cancer patient advance directive writing. Methods: To evaluate the effects of video education on cancer patient advance directive knowledge, attitude, writing intention and writing, this study employed a non-equivalent control group and non-synchronized design as a quasi-experimental study. The target population of this study were adults aged ≥50 years old, diagnosed with cancer in South Korea. The proximity population were also cancer patients who visited a university hospital. The control group (n=31) were educated verbally using a leaflet and the experimental group (n=30) were educated by a video program developed by the National Bioethics Policy Institute for 10 minutes, supplemented with a leaflet. The advance directives video program form provided by the Korean Ministry of Health and Welfare was used. Results: The experimental group showed a positive change in knowledge level (F=52.82, p<.001, effect size=0.96), attitude (F=12.21, p<.001, effect size=0.46), the intention to write (F=18.22, p<.001, effect size=0.56) advance directives and a higher proportion of writing (χ 2 =13.87, p<.001) than the control group. Conclusion: The results of this research show that providing information through video is a more effective educational medium for retention of knowledge, attitude, writing intention, and writing of cancer patient' s advance directives.