A familial syndrome of partial lipodystrophy inherited as a dominant trait is reported. Subcutaneous fat loss was confined to the extremities and trunk. Diabetes mellitus, hyperlipidemia, hepatomegaly and renal disease were very prevalent in this family. Metabolic studies were performed on 3 members. In vivo tests suggested that the remaining fat tissue responded normally to stimulators and inhibitors of lipolysis. In vitro incubation of the dystrophic fat tissue of one patient suggested that the intracellular pathways of lipid and glucose metabolism were normal. The pattern of subcutaneous loss of adipose tissue observed in this family may be due to sympathetic nervous system overactivity of certain non-contiguous dermatomes.