Epstein's triad which is a syndrome with the combination of macrothrombocytopenia, deafness and nephritis, is similar to Alport's syndrome. We report on a case of Epstein syndrome and describe the results of morphological examination of a renal biopsy, specimen. The patient was a 14-year-old girl with the diagnosis of chronic idiopathic thrombocytopenic purpura that had preseated from the age of 3 years. She was referred to Daisan Hospital of the Jikei University School of Medicine on April 1, 1991 for refractory thrombocytopenia. She had shown sensorineural hearing loss since the age of 6 years and her peripheral blood smear revealed giant platelets on admission. She was treated with interferon, prednisolone, and high-dose gamma-globulin (400 mg/day x 5 days). However, the platelet count did not increase, but hypermenorrhea continued. She subsequently showed proteinuria and hematuria. She underwent splenectomy and renal biopsy on August 12, 1992. The glomeruli appeared to be almost normal under light microscopy. The interstitium showed regional fibrosis containing foam cells and the renal tubuli showed mild atrophy. Under electronmicroscopy, the basement membrane of the glomeruli was associated with mesangial interposition and the lamina densa was split into several layers. These ultrastructural findings were compatible with those of Alport's syndrome.