Four patients with active acromegaly were treated for 18 to 180 days with 2-Br-α-ergocryptine(CB-154), and the following results were obtained. 1). Two patients showed an improvement in glucose tolerance with short term treatment with CB-154, and other patients showed a change in their voice and a reduction in soft tissue thicking with long term treatment. 2). The effect of CB-154 on LH-RH induced hGH release was studied in 2 patients with active acromegaly. In a patient whose hGH levels were suppressed by administration of CB-154 (CB-154 responder), CB-154 completely blocked LH-RH induced hGH release, whereas in a CB-154 non-responder CB-154 did not block LH-RH induced hGH release. 3). Under CB-154 administration plasma hGH concentration fell remarkably during awake, but plasma hGH level during sleep was not suppressed in patients with active acromegaly. These results suggest that CB-154 is a potent drug for the treatment of acromegaly and act on both superior centers, the hypothalamus and the pituitary gland.