This study aimed to evaluate the contents and readability levels of informative texts about anterior cruciate ligament (ACL) on Turkish websites. In this cross-sectional study, online searches were performed using the Google, Yandex, and Yahoo search engines on 16, 17, and 18 November 2020, respectively. In these three search engines, 'anterior cruciate ligament', 'anterior cruciate ligament surgery', 'ACL', and 'ACL surgery' were entered in Turkish. The first 10 pages from each search on the websites were collected. The websites were divided into 3 groups according to their sources. Group 1 was classified as websites prepared by private hospitals or medical centers; group 2, as individual websites of orthopedics and traumatology physicians; and group 3, as non-profit websites providing general health information that does not fall into these two groups. The websites were analyzed based on both the website interface and a specific content scoring guide by two reviewers. The Flesch Kincaid (FK) grade level and the Flesch reading ease (FRE) score were used to determine the readability of information on the websites. Eighty-five unique websites were evaluated. The mean quality score of all the websites was 10.4 ± 4.5 with a maximum score of 25 (range=3-21). No significant difference in quality score was found between the groups. The mean FK grade score of all the websites was 11.2 ± 1.7 (range=7.9-15.3). The mean FRE score of all the websites was 46.8 ± 7.7 (range=24.1-63.7). No statistically significant differences in FK grade and FRE score were found between the groups. Although 59 websites (69%) had a third-party seal indicating the certification of one of the organizations established to provide a standard of health information on the Internet, only 21 websites (25%) were updated in the year before the search. The readability level of the informative texts about the ACL on the Turkish websites was above the educational level in Turkey. In addition, the quality score of the Turkish websites related to ACL was low. The content of the informative texts should be organized while taking into account the patients' literacy level.