Adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome (CS) is mostly due to unilateral tumors, with bilateral tumors rarely reported. Its common causes include primary pigmented nodular adrenocortical disease, ACTH-independent macronodular adrenal hyperplasia, and bilateral adrenocortical adenomas (BAAs) or carcinomas. BAAs causing ACTH-independent CS are rare; up to now, fewer than 40 BAA cases have been reported. The accurate diagnosis and evaluation of BAAs are critical for determining optimal treatment options. Adrenal vein sampling (AVS) is a good way to diagnose ACTH-independ