Introduction: In recent years, YouTube has become an important platform for sharing healthcare information. The aim of this study was to investigate the quality of YouTube videos on colon cancer and to characterize the available information. Methods: A YouTube search was performed using the keywords “colon cancer”, “colon cancer symptom”, and “colon cancer surgery”. Two researchers analyzed the videos for source, length, number of views, number of likes, and days since upload. A usefulness score was used to categorize the videos into “useful”, “slightly useful”, “not useful”, “misleading”, or “useful only for medical personnel”. Additionally, a comprehensiveness score (0˜10) was evaluated, as well as audio quality (1˜3) and video quality (1˜3).Table: Table. Video demographics according to usefulness scoreTable: Table. Video demographics according to upload sourceResults: After filtering about 1,935,000 potential videos, 84 videos were included for analysis. 29 videos (34.5%) were “useful”, 30 videos (35.7%) were “slightly useful”, 10 (11.9%) were “not useful”, 5 (6.0%) were “misleading” and 10 (11.9%) were “useful only for medical personnel”. Among the 29 “useful” videos, 24 videos (82.8%) were uploaded by medical professionals or medical websites. On the other hand, among the 5 “misleading” videos, 4 videos (80%) were uploaded by independent civilians. A correlation was found between the usefulness score and comprehensiveness score (Spearman's rank correlation co-efficient=0.581, P<0.001). There was no correlation between usefulness score and the number of views, the number of likes, or the length. Conclusion: Although YouTube has a substantial amount of useful information about colon cancer, it seems that viewers do not have easy access to useful videos. Upload source, comprehensiveness score are a potential filter for useful information.