Purpose The aim of this ESSKA consensus is to give recommendations based on evidence and expert opinion to improve diagnosis, preoperative planning, indication and surgical strategy in ACL revision. Methods The European expert surgeons and scientists were divided into four groups to participate in this consensus. A "literature group" (four surgeons); "steering group" (14 surgeons and scientists); "rating group" (19 surgeons) and inally "peer review group" (51 representatives of the ESSKA-ailiated national societies from 27 countries). The steering group prepared eighteen question-answer sets. The quality of the answers received grades of recommendation ranging from A (high-level scientiic support), to B (scientiic presumption), C (low level scientiic support) or D (expert opinion). These question-answer sets were then evaluated by the rating group. All answers were scored from 1 to 9. The comments of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the question-answer sets were submitted to the peer review group. A inal combined meeting of all the members of the consensus was held to ratify the document. ResultsThe literature review for the diagnosis and preoperative planning of ACL revision revealed a rather low scientiic quality. None of the 18 questions was graded A and six received a grade B. The mean rating of all the questions by the rating group was 8.4 ± 0.3. The questions and recommendations are listed below. Conclusion ACL revision surgery is a widely debated subject with many diferent opinions and techniques. The literature reveals a poor level of standardisation. Therefore, this international consensus project is of great importance. Level of Evidence II.