Temporomandibular joint（TMJ）ankylosis is defined as a pathology causing severe limitation of joint mobility by filling of the gap between the mandibular condyle head and mandibular fossa with fibrous or osseous tissue. 　We report our clinical experience with a case of recurrent TMJ ankylosis resulting from gap arthroplasty. At the initial visit, the patient’s maximum mouth opening was 17 mm and hard trismus was felt. X-rays showed narrowing of both TMJ gaps, and fibrous adhesions and ankylosis on the left side were suspected. Therefore, we performed a gap arthroplasty. Thereafter, the patient did not perform postoperative mouth-opening exercises, and so we educated the patient before a second procedure, and the patient performed aggressive, continuous mouth-opening exercises postoperatively. One year postoperatively, the maximum mouth opening was 35 mm and there had been no recurrence.