Study Objective: Nonsuicidal self-injury (NSSI), the deliberate destruction of one's body tissue (eg, self-cutting, burning) without suicidal intent, has consistent rates ranging from 14% to 24% among youth and young adults. Moreover, youth who enact NSSI are at risk for repeated NSSI, interpersonal difficulties, additional psychiatric symptoms, and, in some cases, suicide. With more youth using videosharing Web sites (YouTube), this study will examine the accessibility and content of nonsuicidal self-injury videos online.Methods: This is a retrospective content analysis study. Using YouTube's search engine, data was collected by searching for videos on YouTube using the key words "self-injury" and "self-harm." Videos were identified and viewed between October 2014 and December 2014. Standardized forms were used for data abstraction. Beyond coding for video purposes, video tones (eg, educational, encouraging, angry) were also examined. Many videos may have more than 1 NSSI method depicted; many may also have more than 1 body location. Viewers' comments from the NSSI videos on YouTube were examined as an index of viewer response using two coding rubrics, one for the global nature of comments and one for recovery-oriented themes. All videos were analyzed independently by 2 researchers and disagreements resolved by an arbitrator. Descriptive statistics and frequency tables were used to describe research findings. Interrater reliability was determined using the Kappa score.Results: During the 3-month study period, 92 YouTube videos of depicting NSSI were identified. The videos were collectively viewed over 10 million times; the mean number of views per video was 236,811. These videos were marked as a "favorite" a total of 224,734 times with an average of 2470 times per video. Specifically, 84% of videos had visual depictions (eg, photographs) of NSSI. Overall, cutting was the most commonly depicted NSSI method, followed by self-embedding, burning, and then, less frequently, acts including hitting, biting, skin picking, and wound interference. Forty videos (43%) featured a live person (ie, character videos) and 52 were non-character videos. Noncharacter videos depicted more graphic NSSI imagery and multiple NSSI methods (eg, cutting, burning). The majority of the people (88%) identified in the videos were Caucasian; 84% were female. The estimated age of participants was 10 to 15 years in 23% of the videos, 16-20 years in 59%, and > 20 years old in 18%. Only 27 of these videos (29%) posted trigger-warnings, intended to warn users that Web site content may trigger NSSI. The majority of NSSI videos had informational content (ie, presented NSSI facts) and/or "melancholic/hopeless" (ie, emphasized emotional pain) messages. Responses consisted of viewers sharing their own NSSI experiences (41%), validating or praising uploaders for their videos (22%), or encouraging the uploader (13%). Few discussed or mentioned NSSI recovery; most comments indicated that the individual was still injuring.Conclusions: The depiction of NSSI ...