Background: Video material is one of the most common types of digital information on social media platforms. Purpose: To assess the validity and informational value of TikTok videos with regard to the anterior cruciate ligament (ACL). Study Design: Cross-sectional study. Methods: Using the terms “anterior cruciate ligament” AND/OR “ACL,” 420 TikTok videos were retrieved, of which 100 videos were included in the analysis. The video duration and the number of likes, shares, and views were recorded. Videos were categorized based on the source (private user, physical therapist, surgeon, and researcher), subject type (patient experience, physical therapy, injury mechanism, anatomy, clinical test, and surgical technique), content (patient experience/testimony, education, and rehabilitation), and any background audio (music or voice). Video quality assessments were conducted using the DISCERN instrument, The Journal of the American Medical Association ( JAMA) benchmark criteria, and the Global Quality Score (GQS). Associations between quantitative variables were tested using the Spearman rank correlation. One-way analysis of variance or Mann-Whitney test was performed to assess whether video quality differed by video characteristics. Results: A total of 41 videos were published by private users (41%), 34 by physical therapists (34%), 23 by surgeons (23%), and 2 by researchers (2%). Most of the information regarded patient experience (34%), followed by physical therapy (20%), injury mechanism (19%), anatomy (11%), clinical test (9%), and surgical technique (7%). The mean video length was 40.55 ± 41.58 seconds. The mean number of views was 151,084.39 ± 487,150.02, while the mean numbers of comments, likes, and shares were 72.80 ± 249.68, 6781.49 ± 29,163.96, and 98.71 ± 307.76, respectively. The mean DISCERN, JAMA, and GQS scores were 15.73 ± 1.44, 0.19 ± 0.39, and 1.16 ± 0.37, respectively, indicating the poorest quality on all 3 indices. The number of views, likes, shares, comments, and video lengths were all positively correlated with DISCERN (except the number of shares), JAMA, and GQS scores ( P < .05). A significant difference was found in DISCERN scores between videos by private users and those by surgeons (15.37 ± 0.98 vs 16.22 ± 1.57; P = .007). Conclusion: Our analysis has demonstrated that the educational value of these videos on the ACL on TikTok is poor. Given the rapid growth of TikTok, further research is needed.