Cushing's disease is the most common cause of Cushing's syndrome in children and is almost always related to over secretion of ACTH by the pituitary gland. It is important to identify a secreting adenoma prior to surgery. Seven cases studied with MRI are reviewed. In five cases the MRI findings suggested adenoma. Three secreting adenomas were confirmed at surgery. One case was in fact a cyst of the pars intermedia, and nothing could be found in the last case. Two patients presented with apparently normal findings on MRI, which was confirmed. There is a close correlation between identifying an adenoma and the success of surgery.