Background: The general population is increasingly using YouTube as a source of information on breast cancer, the most frequent cancer among women. Arabs are the most interested population in breast cancer on YouTube. The transmission of accurate information is important to reduce mortality rates. This cross-sectional study aims to evaluate breast cancer videos on YouTube in the Arab world. Methods: A YouTube search for "breast cancer" in Arabic was performed. The most viewed 60 videos included were evaluated for global quality (GQS score), reliability (modified DISCERN score), content (content score), and misleading claims. Recorded and calculated data included views, duration, videos power index, and viewers' interaction. Sources from legal persons (governments, universities, TV channels, physicians' groups), and blogs (online health channels, individuals) were categorized. Results: The median global quality (3/5), reliability (2/5), and content scores (4/11) were overall low. Misleading information was found in 42% of the videos. Although videos uploaded by legal persons were less popular (163,454 vs 327,488 views), they hosted more physicians (52% vs 15%), were less misleading (15% vs 64%), covered more content, and were of higher global quality and reliability than videos uploaded by blogs [p < 0.05]. While the topic of symptoms (55%) was discussed the most, genetic counseling (13%) and prevention (20%) were the least mentioned. Conclusions: YouTube is poorly informational and inaccurate on breast cancer in the Arab World where it is highly used. Although videos uploaded by legal persons tend to be more adequate, they are of lower popularity. Governments and physicians are encouraged to upload more intelligibly informational videos, guide the population to reliable sources, and support regulations. [ABSTRACT FROM AUTHOR]