We compared embolectomy (when available) with thrombolysis in patients with shock and massive pulmonary embolism. 13 patients were operated on, 10 (77%) of whom survived. The inferior vena cava was routinely clipped. The 24 medically treated patients were given alteplase until systemic and pulmonary artery pressures stabilised and heparin thereafter; 16 (67%) survived. Major haemorrhage occurred in 28% of medically treated patients, but was not fatal. 1 patient had a small cerebral haemorrhage that resolved without drainage. One-fifth of the medical group had a re-embolism, which suggests that temporary caval umbrellas are indicated in medically treated patients. Thrombolysis may provide a life-saving option and a randomised trial is warranted.