We measured the serum adiponectin and leptin concentrations before and after successful removal of a left adrenal adenoma in a 46-year-old woman with Cushing's syndrome. The serum adiponectin level was 6.0 microg/ml before the operation and rose to 8.1 microg/ml after adrenalectomy. However, the serum leptin level was markedly high (24.8 ng/ml) before the operation and decreased to within the normal range (6.0 ng/ml) 6 months after adrenalectomy, concomitant with weight reduction and normalization of the serum cortisol level.