The syndromes of partial and of total lipodystrophy have been reviewed and 27 further patients added, 25 with partial lipodystrophy and 2 with total lipodystrophy. For inclusion in the syndrome of partial lipodystrophy symmetrical loss of fat from the face with or without truncal loss, but with retention of distal adipose depots was required. In total lipodystrophy fat loss was generalized. A number of additional features were commonly present in total lipodystrophy. These included increased height, advanced bone age, hirsuties, pigmentation, prominence of muscles, abdominal protuberance, penile or clitoridial enlargement, hepatomegaly, relatively insulin resistant hyperglycemia, hyperlipemia and hypermetabolism, as well as renal disease, disturbances of C.N.S. function and cardiomegaly. Review of reports of patients with muscular hypertrophy suggested that several so described might have had total lipodystrophy. A significant incidence of renal disease was encountered in the reports of partial lipodystrophy in the literature and more particularly in the group presented. Although much less frequently present, central nervous system dysfunction, hepatomegaly and a decreased glucose tolerance were also noted. It appears that there are features common to both syndromes other than disappearance of fat. Possible pathogenetic mechanisms have been considered.