There have been few reports on successful treatment for focal segmental glomerulosclerosis (FSGS) complicated by leukoencephalopathy. We report the efficacy of the steroid pulse and mizoribine (MZB) combined with plasmapheresis (PP) for a case of FSGS with leukoencephalopathy induced by cyclosporine (CyA). The patient was a 4-year-old boy with FSGS who presented with steroid-resistant nephrotic syndrome (NS) and was treated with CyA. On the 7th day after starting CyA, he complained of one visual disorder, and hypertension and tonic convulsions were observed. Electroencephalography (EEG) revealed generalized slow waves, and magnetic resonance imaging (MRI) disclosed high signal intensity in the white matter. A diagnosis of leukoencephalopathy induced by CyA was made on the basis of these findings with the improvement in clinical manifestations upon discontinuation of CyA. We treated the patient with steroid pulse therapy and MZB combined with PP, and the proteinuria gradually decreased and only microscopic hematuria remained. We report that steroid pulse and MZB combined with PP may be an effective treatment in a patient with FSGS complicated by CyA-induced leukoencephalopathy.