The present report illustrates the effectiveness of a long-acting somatostatin analog, SMS 201–995 (Sandostatin), in the chronic treatment of acromegaly. Daily doses of 50-300 µg were administered subcutaneously to 37 patients. Gradual dose increments induced a progressive GH decrease accompanied by a parallel reduction in plasma somatomedin C concentrations. There was a concomitant amelioration of clinical signs and symptoms throughout the investigational period. No escape phenomenon or tachyphylaxis was observed. It is concluded that chronic therapy with SMS 201–995 represents a promising medical alternative for the treatment of active acromegaly.