A 21-year-old woman presented with bilateral optic neuritis, combined with central retinal vein occlusion. General physical examination and neurologic consultation revealed no other findings. Laboratory investigation yielded an elevated erythrocyte sedimentation rate, positive LE preparation, elevated ANA titer, and elevated blood urea nitrogen and creatinine levels. Diagnosis of systemic lupus erythematosus (SLE) was made. Renal failure developed quickly and she was treated with hemodialysis, transfusion and subsequently systemic corticosteroid. Anti-phospholipid antibody was positive to lupus anti-coagulant and the titer was normalized after 2-month steroid therapy at which time the visual outcome differed between the eyes. The right eye showed improvement in visual acuity and visual field, but the left eye was not improved and retained a central scotoma. SLE needs to be considered in young women with optic neuritis when other causes of optic neuritis have been excluded, and serologic tests including anti-phospholipid antibody should be conducted.