Treatment of massive osteochondral defects of the medial femoral condyle is challenging. A 46-year-old man who had a medial femoral condyle fracture on his left knee underwent osteosynthesis in a hospital, but the pain remained and the patient was referred to our hospital 8 months after the surgery. Radiographs showed a varus alignment of the leg, and magnetic resonance image showed a massive necrotic area in the medial femoral condyle. The patient received high tibial osteotomy (HTO) combined with iliac cancellous bone graft and an osteochondral autograft transplantation. Pain and the knee function markedly improved 2 years after the surgery. A second look arthroscopy showed a well-covered bone graft site with cartilaginous tissue and a well-integrated osteochondral plug. HTO combined with cancellous bone autograft and osteochondral autograft transplantation could be an effective treatment for patients presenting with a varus knee deformity associated with massive osteochondral defects in the medial femoral condyle.