In patients with ischemic stroke the risk of provoking hemorrhagic infarction must be balanced against the risk of deep vein thrombosis and potential pulmonary thromboembolism. In a retrospective study we reviewed the records of 262 ischemic stroke patients admitted in 1984 and of 315 patients admitted in 1988. In 1984 only six (2.3%) patients were treated with low-dose subcutaneous heparin, while 126 (40%) in 1988. In 1984 seventy-five (28.6%) patients died and in 48 of them post-mortem examination was performed, while in 1988 seventy-four (23.5%) patients died and in 30 of them the autopsy was performed. Pulmonary embolism was revealed in 25 patients on post-mortem examination in 1984 and none of them was treated with heparin. In 1988 only eight patients (two were on heparin) had pulmonary embolism. Hemorrhagic infarction was found in only seven cases (only two of them were on heparin) of all pathological examinations. We conclude that preventive low-dose subcutaneous heparin is safe and effective in decreasing mortality due to pulmonary embolism in patients with ischemic stroke.