The authors report a case of systemic lupus erythematosus with posterior leukoencephalopathy who presented with headache, tonic-clonic seizure, loss of consciousness and bilateral loss of vision, after taking azathioprine for three weeks. The patient had hypertension with normal eye grounds. The brain CT showed a hypodensity lesion at both bilateral occipital lobes, mainly in the white matter The symptoms and follow-up MRI were improved after the control of hypertension and discontinuation of azathioprine.