A case of a 47 years old patient without complicating diseases with disturbing auditory hallucinations after 24 hours morphine treatment is described. Morphine was administered for postoperative analgesia after probatory laparotomy in a dose of 10mg SC every 4 hours. The hallucinations were associated with a weak external stimulation (noise from monitors and air conditioning) and were presented as a harmonic music (Russian choirs). Sometimes, the patient had visual sensations after closing his eyes. Most probably, the cause was morphine, because after its withdrawal and substitution with tramadol hallucinations disappeared during 24 hours. Similar cases are described as a rare complication of morphine therapy in geriatric terminally ill patients and are not completely understood.

        Key words: morphine – postoperative analgesia – hallucinations