Osteochondral lesions of the talus (OLTs) involve varying regions of the talar dome articular cartilage and underlying subchondral bone. Large OLTs include significant portions of the weight-bearing dome and may be encountered both medially and laterally. These lesions have been demonstrated to have poor healing potential, largely because of tenuous vascular supply, and may lead to progressive degenerative joint disease. For large, expansive OLTs, and those involving the shoulder region of the talus, other cartilage restoration procedures, including microfracture, osteochondral autograft transplantation, and juvenile chondrocyte implantation, may be inadequate and lead to failure. Osteochondral allograft implantation has emerged as a promising treatment option for large OLTs because it provides both structural support and self-sustaining, viable chondrocytes. However, adequate access to the talar dome is critical for allograft implantation. Medial malleolar osteotomy has emerged as a reliable and safe method for exposure of the talar dome and shoulder region. Careful technique is essential to avoid poor outcomes and to ensure consistent results. This video overview and case presentation demonstrate a technique for fresh osteochondral allograft implantation of a large OLT of the talus through a medial malleolar osteotomy. An overview of the pathogenesis, diagnosis, and management of OLTs is provided, followed by indications for osteochondral allograft implantation of talar dome osteochondral defects. A case of a 16-year-old boy with a large traumatic OLT of the talus is presented. The patient previously underwent ankle arthroscopy with autologous stem cell and extracellular matrix implantation but presented with persistent, recalcitrant symptoms. Advanced imaging revealed an incompletely healed, large OLT of the medial talar dome. Fresh osteochondral allograft implantation was performed through a medial malleolar osteotomy. Excellent restoration of the talar articular surface was achieved intraoperatively. The patient advanced through a standardized rehabilitation protocol, with gradual relief of his symptoms. Osteochondral allograft implantation is a reliable treatment option for large or refractory OLTs. Implantation often requires adequate exposure afforded by a medial malleolar osteotomy. Although studies have demonstrated good outcomes, results are contingent on careful and consistent technique, which is reviewed in the video.