Recently, bromocriptine has been successfully introduced as medical therapy for the pituitary hypersecreting syndromes of hyperprolactinemia and acromegaly. Subsequently, an inhibitory effect on ACTH secretion was reported using bromocriptine in Cushing's disease. While most studies have focused on the acute response to bromocriptine, few have investigated the response to chronic therapy with this agent. In this report, we describe a patient with Cushing's disease in whom an acute inhibition of ACTH and cortisol was demonstrated following bromocriptine and in whom the long term administration of bromocriptine as the sole therapy produced a transient beneficial response. Further pharmacologic testing suggested this inhibitory effect on the hypothalamic-pituitary-adrenal axis was mediated through dopaminergic stimulation.