Congenital dislocation of the radial head (CDRH), a congenital anomaly of the elbow, can cause symptoms such as joint stiffness, snapping, locking, or pain, however the diagnosis is sometimes made incidentally from x-rays. The treatment goal is to ameliorate the symptoms and obtain a joint with a full range of motion. This paper presents a case of unilateral CDRH that was asymptomatic until adolescence, when locking and snapping developed. Several treatment options are described in the literature. Although the conventional and computer-assisted external fixator systems are used in several clinical pictures such as extremity deformities, joint contractures and fixation of acute fractures etc a computer-assisted external fixator system has not been used for CDRH. We successfully performed ulnar dorsal translation and a lengthening osteotomy with a computer-assisted external fixator to reduce the radial head indirectly and had satisfactory functional and clinical results.