Focal fibrocartilaginous dysplasia (FFCD) is a rare benign bone lesion, which mainly occurs in the proximal tibia. In the upper extremity, only 21 cases have been reported so far and 14 of these involved the ulna. We present an additional case of FFCD in the distal ulna that showed progressive bowing of the right forearm and the radial head dislocation. Resection of the abnormal tissue, osteotomy of the radius and ulna, and gradual lengthening of the ulna were performed. On the basis of the previously published data of 14 cases and our data, we have summarized the etiology, clinical features, natural history, and treatment of FFCD in the ulna.