We developed a new arthroscopic-assisted drilling method through the radius in a distal-to-proximal direction for osteochondritis dissecans (OCD) of the elbow. Only 1 drill hole is created in the radius by use of a single 1.8-mm K-wire inserted from the shaft of the radius approximately 3 cm distal to the humeroradial joint into the joint, which allows drilling of the entire OCD lesion. The forearm is supinated so that the tip of the K-wire is at the lateral side of the lesion in the humeral capitellum, and drilling is performed at 30 degrees elbow flexion. The flexion angle is changed from 30 degrees to 60 degrees to 90 degrees to 120 degrees while maintaining supination, to drill in 4 sites (1 site for each angle of flexion) of the lateral side of the OCD lesion. Next, we move the forearm from supination to pronation so that the tip of the K-wire is placed in the medial side of the lesion in the humeral capitellum, and as with the lateral side, drilling is performed in 4 sites. With this technique, the entire OCD lesion can be vertically drilled under arthroscopic guidance. This method is minimally invasive, and an early return to sports could be possible.