A case of familial Bardet-Biedl syndrome (BBS) in a 64-year-old woman is presented; it is characterized by abdominal obesity (BMI: 38.28; WHR: 0.98), slight mental retardation, polydactyly, pigmentary retinopathy and moderate renal failure, with insulin-resistant diabetes mellitus and severe inflammation of the left limb with necrosis of the last toe (the sixth) of the left foot. Four brothers and sisters of the patient presented the same syndrome. The patient had had healthy offsprings. The review of current literature indicates that BBS is a genetic autosomal recessive disease, formerly grouped with Laurence-Moon-Biedl syndrome but today considered as a separate entity. It is characterized by obesity, mental retardation, dysphormic extremities (syndactyly, brachydactyly or polydactyly), retinal dystrophy or pigmentary retinopathy, hypogonadism in males, and renal structural abnormalities or functional impairment. Extra- and intrafamilial variability of expressivity and severity of the various clinical manifestations was reported, among affected families and also in the same family. BBS is a rare but important syndrome, that should be known by the endocrinologist and the specialist in internal medicine, because it has an adverse prognosis, with early onset of blindness, insulin-resistant diabetes mellitus and severe renal impairment. Renal failure is a frequent cause of death early in life, even in the infant-juvenile years.