Category: Ankle Introduction/Purpose: Cartilage lesions of the talus are a challenging clinical pathology for orthopaedic surgeons. To date, the treatment guidelines for these lesions have been based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions on key topics regarding cartilage lesions of the talus. Osteochondral autograft and allograft transplantation are surgical modalities to replace the lesion and were discussed as one portion of the first International Consensus Meeting on Cartilage Repair of the Ankle. The purpose of this abstract is to explain the process and delineate the consensus statements derived from this consensus meeting on the use of osteochondral autograft and allograft for osteochondral lesions of the talus. Methods: 75 national and international experts in cartilage repair of the ankle, representing 25 countries and all six continents, were convened and participated in a process based on the Delphi method of achieving consensus. Experts were assigned to groups separated by topics, including osteochondral autograft and allograft. Questions and statements were drafted within the groups and a comprehensive literature review was performed and, where possible, used to confirm or dispute the recommendations made. In addition, the available evidence for each statement was graded. Once the statements achieved majority vote within the working groups, a vote to the overall group was undertaken. The statements were then further edited on the basis of the discussion and votes within the entirety of the consensus group. A final vote then occurred, and the strength of consensus was characterized as follows: consensus: 51 - 74%; strong consensus: 75 - 99%; unanimous: 100%. Results: 29 statements addressing osteochondral autograft and allograft transplantation for cartilage lesions of the talus reached some degree of consensus. These included conclusions on what lesion types/sizes are amenable to this treatment, optimal donor site sources, use of biological augmentation, prognostic factors, and expected outcomes. There was a consensus that: [1] Osteochondral autograft should be considered in primary cystic lesions greater than 1 cm in diameter. [2] The lateral femoral condyle is the preferred osteochondral autograft donor site. [3] It is unnecessary to backfill an osteochondral autograft donor site. [4] Bulk osteochondral allograft transplant should be used in uncontained lesions that cannot be addressed with an osteochondral autograft. No statement achieved less than an 83% consensus following anonymous voting by the expert group. Conclusion: There is a lack of evidence-based guidelines available to direct treatment for clinicians when managing cartilage lesions of the ankle. This international consensus derived from leaders in the field will assist clinicians with a combination of expert- and evidence-based guidelines to consider in the treatment of a cartilage lesion of the talus using osteochondral autograft or allograft transplantation.