The aim of this study was to provide information about long-term functional outcome in patients with isolated oculomotor nerve palsy following minor head injury and to discuss surgical treatment of these patients, especially those with accompanying sphenoid fracture.A retrospective analysis was made of 26 patients with traumatic isolated oculomotor nerve palsy. The severity of oculomotor nerve palsy and the functional recovery were evaluated based on extraocular muscle movement, eyelid movement, and pupil size. On average, patients were evaluated 3.6 days after the initial injury, and the average follow-up period was 14.2 months (range 3 months-2 years).Twenty men and six women were enrolled in this study. The most common cause of trauma was motor vehicle accident in 17 (65.4%) of 26. Among all the recorded symptoms, internal ophthalmoplegia was most frequently seen. The recovery rates of ptosis, external ophthalmoplegia, and internal ophthalmoplegia were 95% (19 of 20 patients), 83.3% (15 of 18 patients), and 50% (13 of 26 patients), respectively. The 6 patients with sphenoid fracture underwent surgical decompression of the superior orbital fissure, after which all patients experienced recovery from ptosis and external ophthalmoplegia and 66.7% (4 of 6 patients) recovered from internal ophthalmoplegia.Limited eye movement may be a major factor that negatively affects functional recovery after mild head injury. Sphenoid fracture might be one of the potential mechanisms involved in traumatic isolated oculomotor nerve palsy after mild head injury. Surgical decompression should be considered when there is evidence of bone compression of the superior orbital fissure.