Generalized congenital lipodystrophy or Berardinelli-Seip Syndrome is a rare autosomal recessive condition characterized by the absence of adipose tissue and eventually a defect in leptin synthesis. Affected subjects tend to show a classical phenotype with acromegaloid appearance, generalized atrophy of subcutaneous adipose tissue with muscular hypertrophy, acanthosis nigricans, hepatomegaly and prominent abdomen. From metabolic point of view and as a consequence of leptin absence, hypertriglyceridemia leading to hepatic steatosis and insulin resistance may appear. Two cases of unrelated subjects affected of generalized congenital lipodystrophy are presented. Both developed difficult-to-manage diabetes mellitus and were treated with high doses of insulin. In both cases early microvascular complications were present. A mutation for LMNA gene was found in one of the subjects.