A 46-year old woman with systemic lupus erythematosus (SLE) who had been treated with oral administration of prednisolone (7.5 mg/5 mg on alternate days) at our outpatient clinic suddenly developed a loss of visual acuity, visual field defect, and photophobia on Dec. 15th, 1993. When she was admitted three days later, she was diagnosed as having optic neuropathy, and immediate treatment with methylprednisolone (1 g/day for three days) followed by prednisolone (50 mg/day) resulted in complete disappearance of the above symptoms by Feb. 9th, 1994. As far as we know, fifty-three cases of SLE with optic neuropathy have been reported previously. The result of analysis of the 54 cases including our case indicates that rapid diagnosis and corticosteroid treatment in an early phase of optic neuropathy leads to significant improvement.