The authors report a series of 22 cases of subdural hematomas in patients submitted to anticoagulant therapy. A review of the literature finds 150 cases. Subdural hematomas occurs in about one third of the patients presenting hemorrhage of central nervous system related to anticoagulant therapy. Among subdural hematomas of any cause, the possible role of a previous anticoagulant therapy is stressed in 4,8 to 14% of cases. In most cases, long term anticoagulants were indicated for arterial or heart (ischemic) lesions (16/22 cases). In 6 cases, anticoagulants were indicated for prevention or treatment of pulmonary embolies. In 18 cases, anticoagulant drug is from the group of dicoumarol or phenylindanedione. In 3 cases, the only anticoagulant given to patient was heparin. Pathogenic study suggests that hypocoagulability might not always be the only factor of bleeding: high blood pressure, other drugs and head trauma (10 cases) are often associated. Clinical features, in our series, are similar to those encountered in cases of subdural hematoma of any cause. According to the existence of a cranial injury and to the chronology of anticoagulant therapy, the authors divide their 22 patients into 3 groups. The use of protamin sulfate or human plasma fraction PPSB provides in few minutes a normal coagulability. Neurosurgical treatment in all our cases evacuated in 11 patients a chronic subdural hematoma, in 2 cases an acute, and in 9 cases a subacute hematoma. Results were fair in 19 patients with no sequelae. 3 patients died during the immediate post-operative period. The authors conclude by stressing several preventive measures.