We present two cases of osteochondritis dissecans of the lateral femoral condyle after the meniscectomy of the discoid lateral meniscus. The first case was a 13-year-old boy who underwent subtotal excision of the right discoid lateral meniscus two years ago. The second case was a 8-year-old girl who underwent subtotal excision of the right discoid lateral meniscus three years ago. In both cases, radiographs showed obvious translucent lesion on the posterior part of the lateral femoral condyle. Arthroscopy showed that there was early separation of the lesion by palpation with a probe in the first case, but no evident softness and swelling of the articular surface in the second case. At surgery, arthroscopic fixation with absorbable pins (PDS) were performed for both cases. At four months after the arthroscopic fixation, radiographs showed good union in both cases and there were no clinical symptoms. Arthroscopic fixation for osteochondritis dissecans of the knee is minimally invasive and effective to ensure the healing of lesions.