This paper presents the most common disorders of pituitary function: acromegaly, hypopituitarism, diabetes insipidus and syndrome similar to diabetes insipidus, in terms of their importance in preoperative preparation of patients. Pituitary function manages almost the entire endocrine system using the negative feedback mechanism that is impaired by these diseases. The cause of acromegaly is a pituitary adenoma, which produces growth hormone in adults. Primary therapy of acromegaly is surgical, with or without associated radiotherapy. If a patient with acromegaly as comorbidity prepares for non-elective neurosurgical operation, then it requires consultation with brain surgeons for possible delays of that operation and primary surgical treatment of pituitary gland. If operative treatment of pituitary gland is carried out, the preoperative preparation (for other surgical interventions) should consider the need for perioperative glucocorticoid supplementation. Panhypopituitarism consequences are different in children and adults and the first step in diagnosis is to assess the function of target organs. Change of electrolytes and water occurs in the case of pituitary lesions in the form of central or nephrogenic diabetes insipidus as a syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Preoperative preparation of patients with pituitary dysfunction should be multidisciplinary, whether it is a neurosurgical or some other surgical intervention. The aim is to evaluate the result of insufficient production of pituitary hormones (hypopituitarism), excessive production of adenohypophysis hormones (acromegaly, Cushing’s disease and hyperprolactinemia) and the influence of pituitary tumours in surrounding structures (compression syndrome) and to determine the level of perioperative risk. Pharmacological suppressive therapy of the hyperfunctional pituitary disorders can have significant interactions with drugs used in the perioperative period.