BACKGROUND: Biopsy of a dorsal mesencephalon lesion often leads to neuro-ophthalmological complications, namely dorsal mesencephalic syndrome, skew deviation, IV (th) palsy, or Horner's syndrome. HISTORY AND SIGNS: A 26-year-old man underwent a biopsy of the quadrigeminal plate for a lesion which revealed to be neurosarcoidosis. Post-operative complications included a left homonymous hemianopia, a left III (rd) nucleus palsy, a bilateral IV (th) palsy and a bilateral internuclear ophthalmoplegia. Palpebral fissures were narrowed to 2 mm on both sides. In primary gaze there was 24 degrees of exotropia, 17 degrees of right hypertropia and 30 degrees of exyclorotation. THERAPY AND OUTCOME: After 24 months of stable evolution, three oculomotor surgical procedures were performed including: surgery on both horizontal muscles of the left eye; shortening of both superior oblique muscles; resection of the right lateral rectus muscle, and posterior fixation of an inferior rectus muscle. Bilateral brow suspension on the frontal muscle of both superior eyelids was then performed. Evolution was favorable with a binocular single field of vision measuring 17 degrees horizontally and 20 degrees vertically centered on the primary gaze. Palpebral fissures measured 7 to 8 mm in primary gaze. CONCLUSIONS: The neuro-ophthalmological sequelae which followed the biopsy of a neurosarcoidosis lesion of the quadrigeminal plate were so severe that this patient was completely handicapped. A four-step surgery correcting the horizontal, torsional, vertical components, then the bilateral ptosis allowed the patient to recover both a satisfying function and esthetical aspect.