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Chondroblastoma usually arises in the long bones at 10 to 20 years of age, but rarely involves the temporal bone. A case of chondroblastoma of the left temporal bone presenting with left hearing loss is reported. This case was 42 year-old woman. She noticed left hearing loss after cold in May, 2006. She underwent medical treatment at a local otolaryngologist, but her hearing did not improve. She was then referred to our hospital for further examination on May 12.Her past and family history were negative.A temporal bone X-ray showed a large and round bone defect at the squamous part. CT and MRI revealed a bone defect and a round tumor shadow, extending from the squamous part to the middle cranial fossa.A biopsy taken from the lateral part of the tumor showed a benign tumor with bony origin. Surgery was performed on 21 Aug. 2006 with collaboration of a neurosurgeon. Lateral skull incision was made to expose the tumor, temporal bone, mandibular joint and the middle cranial fossa. The tumor occupied the epitympanum, base of the zygomatic arch and the squamous part, extending to the infratemporal and the middle cranial fossa. The dura was separated from the tumor. The malleus head was eroded, but the incus and stapes were intact. Facial nerve was preserved. The mandibular joint capsule was partly removed. A prototyped 3D bone model was very useful to get a surgical orientation. Postoperative course was uneventful, leaving moderate conductive deafness. Pathological diagnosis was chondroblastoma. Although chondroblastoma is pathologically benign, recurrence is not rare. This case has also been scheduled for regular follow-up.