Objective: Fascicular oculomotor nerve involvement is occasionally seen in Behcet's disease, but nuclear involvement is very rare.

Case presentation: A 25-year-old woman presented with the Behcet's symptoms and the left eye problems. Physical examination revealed muco-cutaneous lesions, eyelid ptosis, mydriasis, upward and medial gaze palsy and lateral deviation on the left eye. Serologic tests were positive. An inflammatory lesion was detected in the left oculomotor nerve nucleus on magnetic resonance imaging. Neuro-Behcet's disease was considered the most likely diagnosis.

Result: Dexamethasone treatment was ordered. Muco-cutaneal lesions, laboratory abnormalities were normalized after 1 year; but oculomotor nerve palsy persisted in spite of improvement in radiological findings.

Conclusion: Clinical signs of oculomotor nerve palsy may persist despite the radiological improvement.