The Laurence Moon-Bardet Biedl syndrome is characterized by obesity, mental retardation, visual impairment with retinitis pigmentosa, polydactyly, hypogonadism and renal manifestations. We experienced an 11 years old female with Laurence Moon-Baret Biedl syndrome associated chronic renal failure. She was diagnosed to have LMB syndrom according to the clinical manifestations of polydactyly on hands and feet, mental retardation, obesity, retinitis pigmentosa and chronic renal failure. She is on maintenance hemodialysis now.