Objectives: This study aimed to evaluate the quality and reliability of the most viewed YouTube videos on piriformis syndrome (PS) exercises and identify criteria that may be important for selecting high-quality and reliable videos. Materials and methods: We searched for the keywords "piriformis syndrome exercise," "piriformis syndrome rehabilitation," "piriformis syndrome physical therapy," and "piriformis syndrome physiotherapy" on November 28, 2021. The modified DISCERN (mDISCERN), and the Global Quality Score were used to evaluate the quality and reliability of the videos. Results: Of the 92 videos evaluated, most (58.7%) of the videos were shared by healthcare professionals. The median mDISCERN score was 3, and most of the videos were found to be medium or low quality. Videos with more subscribers (p=0.001), a shorter upload duration (p=0.001), videos uploaded by physicians (p=0.004), and videos uploaded by other healthcare professionals (p=0.001) were found to have high reliability. Conversely, videos uploaded by independent users were found to have low reliability (p<0.001). When the parameters of the videos were compared among the quality groups, significant differences were found in all video features (p<0.05), some upload sources (other healthcare professionals and independent users; p=0.001), and mDISCERN scores (p<0.001). Conclusion: It is beneficial for physicians and other health professionals to upload more videos about health to increase the amount of reliable and high-quality information.