Many patients seek information online, including on social media, regarding various health topics. This study aimed to investigate whether YouTube videos on endometriosis could be a useful source for the general population, surgical trainees, and specialists. A YouTube search was conducted on December 26, 2021, using the search terms "endometriosis," "endometrioma," and "endometriotic cyst." Videos were sorted by view count, and the 100 videos with the highest view counts were chosen. After excluding 48 videos for various reasons, 52 were included in the final analysis. The number of views, duration, likes and dislikes, content type, and source of each video were recorded. We referred to a previous study to evaluate video quality. The 52 videos related to endometriosis had a total of 35,220,141 views (median 233,688, range 48,874-10,452,366). Based on authorship, the videos were categorized into videos uploaded by the medical group and the nonmedical group. The medical group mainly uploaded videos directly related to endometriosis, such as explanations or detailed surgical procedures for endometriosis (26/27, 96%), whereas the nonmedical group mainly uploaded videos about personal experiences and others (24/25, 96%; P <.001). Evaluating the score by each type of content, videos containing personal experiences (median score 6, range 3-10) scored significantly lower than videos containing other content such as explanations of the disease (median score 14, range 7-18; P < .001) and surgical procedures (median score 9, range 5-17; P < .001). Analysis according to the source, the number of views and video power index was significantly higher in the videos uploaded by the nonmedical group (P < .05). YouTube is currently not an appropriate source for patients to gain information on endometriosis. Credible videos with accurate information and clear, highquality operative clips with proper scientific commentary should be uploaded by medical professionals and medical institutions to critically and rapidly appraise the quality of online video-disseminated information on endometriosis. In addition, advanced filtering using categories by YouTube's staff appears to be necessary.Abbreviations: ICC = intraclass correlation coefficients, VPI = video power index.
