Cushing's disease is a disorder of hypercortisolism caused by a pituitary micro- or macro-adenoma. Most patients with Cushing's disease have a bilateral adrenal enlargement, which depends on the duration of the disease, as a result of the long standing ACTH stimulation of both adrenal glands. However, in macronodular adrenocortical hyperplasia (MNH) that is caused by Cushing's disease, if the MNH gains autonomy, a bilateral adrenalectomy, as well as the removal of pituitary adenoma, is often essential. We encountered a patient diagnosed with Cushing's disease with bilateral adrenal tuberculosis simulating MNH. She had taken anti-tuberculosis medications one year prior to admission due to spinal tuberculosis. Sellar MRI revealed a pituitary macroadenoma, but adrenal CT showed enlargement in both adrenal glands that appeared to be MNH. A hormonal study and bilateral inferior petrosal sinus sampling revealed Cushing's disease. Therefore, she underwent trans-sphenoidal surgery of the pituitary mass. The pituitary surgery was successful and the serum cortisol returned to normal range. However, the adrenal mass rapidly enlarged after removing the pituitary tumor without showing evidence of a recurrence or adrenal autonomy of hypercortisolism. Accordingly, a laparoscopic left adrenalectomy was performed to examine the nature of the mass. The resected left adrenal gland was pathologically determined to have a lesion of tuberculosis with some part of the intact cortex. So we assumed that the cause of rapid adrenal enlargement might be due to adrenal tuberculosis. In summary, to the best of our knowledge, this is the first case of Cushing's disease coexisting with both adrenal tuberculosis simulating a bilateral MNH.