Cardiovascular complications, including cardiomegaly, myocardial ischemia and left ventricular hypertrophy, are some of the major determinants of the mortality rate in patients with Cushing's syndrome. We herein report the case of a patient with Cushing's syndrome caused by an adrenal adenoma who presented with congestive heart failure secondary to dilated cardiomyopathy. Follow-up echocardiography showed a marked improvement in the left ventricular cardiac function, and the plasma B-type natriuretic peptide (BNP) levels regressed after successful treatment. "Reversible" dilated cardiomyopathy is rarely associated with Cushing's syndrome; however, it should be recognized. Administering appropriate treatment in a timely manner can reverse this cardiomyopathy along with the other symptoms of Cushing's syndrome.