Lene Rahr-Wagner, Martin Lind Department of Orthopaedic Surgery, Division of Sports Surgery, Aarhus University Hospital, Aarhus, Denmark Abstract: The Danish Knee Ligament Reconstruction Registry was established in 2005 as a web-based nationwide clinical database with the purpose of improving the monitoring and quality of both primary and revision knee ligament reconstructions in Denmark. All primary and revision anterior and posterior cruciate ligament reconstructions as well as collateral ligament and multiligament reconstructions are recorded. Main variables include sex, age, cause of injury, objective ligament instability, and surgical data, such as affected ligament, graft- and implant choice, operation technique among other things. The operating surgeon prospectively collects the data. Hence, detailed preoperative, intraoperative, and 1-year follow-up data are recorded by the operating surgeon using a standardized form and a secured Internet portal. The number of procedures registered in the database each year is ~2,500 and the first 9 years, in total, 22,775 procedures have been registered. Since the beginning of the database multiple papers have been published in international peer-reviewed journals, improving the knowledge of patients treated with knee ligament reconstruction surgery. This paper reviews the content, organization, and published research from the Danish Knee Ligament Reconstruction Registry. Keywords: ligament reconstruction, anterior cruciate ligament, operation technique, database, graft choice, femoral tunnel drilling, patient-reported outcome measure