The simultaneous onset of edema in identical twin girls led to the diagnosis of the nephrotic syndrome. Light microscopy revealed minimal histological changes of their renal biopsy specimens. Epithelial cell foot process fusion was demonstrated by electron microscopic examination of the biopsy specimen of patient 2. Prompt remission of their disease occurred following prednisone therapy. Similar appearance, sex, dermal ridge patterns, and identical multiple blood groups were evidence of their monozygotic relationship.