SUMMARYThe therapeutic effect of transsphenoidal hypophysectomy with cryoapplication has been studied in twenty‐nine patients with active acromegaly. The mean follow‐up time was 15 months (3‐54 months).A significant improvement of symptoms and signs occurred in all but three patients. The level of plasma immunoreactive growth hormone (IRGH) was reduced in all but two patients and a normal level of plasma IRGH was achieved in sixteen patients. Skin thickness, the level of serum inorganic phosphorus and the urinary excretion of hydroxyproline and calcium were significantly decreased in the great majority of the patients.The operation was not accompanied by any visual complications, but cerebrospinal rhinorrhoea, subsiding spontaneously, developed in two and postoperative meningitis in one patient. Hypothyroidism and adrenocortical deficiency developed in eight, gonadotrophin deficiency in thirteen, and persistent diabetes insipidus in one patient.It is concluded that transsphenoidal hypophysectomy with cryoapplication is a safe and effective method for the treatment of acromegalic pat