The case-history presents a case of unexpected pulmonary embolization manifestated in a middle-aged patient closely before operation (classical cholecystectomy).The severe respiratory insufficiency was the conse- quence,which proceeded to a metabolic disbalance and the state of disseminated intravascular coagulation.The prognosis was very serious,but the patient recovered after 4 weeks of complete resuscitative care.The authors would like to initiate the discussion about the way and timing of antithrombic preoperative preparation in elderly patients and in those with a high risk of thromboembolic complications.

        Key words: pulmonary embolization – operation –respiratory insufficiency –multiorgan failure