BackgroundYoutube has become an influential source of health. This study aimed to evaluate the reliability and quality of YouTube videos on spasticity. MethodsThe keywords “ spasticity, spasticity treatment, spasticity exercises” were used to search for videos. According to the search results, 180 videos were analyzed, videometric characteristics of the videos were recorded, and 2 groups were formed as health professionals and non-health professionals according to the video source. In addition, low, medium and high quality groups were formed using the global quality score (GQS). The reliability of the videos was evaluated using the modified DISCERN (mDISCERN) scale. Video popularity was assessed using the video power index (VPI). ResultsAfter excluding videos that met the exclusion criteria, the remaining 68 videos were analyzed. The videos were uploaded by healthcare professionals (n = 47, 69.1%) and non-healthcare professionals (n = 21, 30.9%). The popularity (VPI), reliability (mDISCERN) and quality (GQS) of videos uploaded by healthcare professionals were significantly higher (p = 0.002, p = 0.001, p = 0.021, respectively). Most of the videos were of high quality according to GQS (n = 40, 58.8%). All of the high quality videos were of healthcare professionals. The number of sources from healthcare professionals was significantly higher in high quality videos than in both low (p = 0.001) and medium (p = 0.001) quality videos. ConclusionWe can conclude that most of the YouTube videos on spasticity are reliable and of high quality. However, it should be kept in mind that patients may be exposed to low-quality and unreliable videos with misleading content.