A review of cases admitted to the "Emergency Service" of the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo during a period of 4 years (1954 to 1957) was made and among them three cases were considered of interest because of the difficulty of diagnosis as well as its rarity. In those patients the evolution and further investigation invalidated the diagnosis of subdural hematoma with which they were admitted. This diagnosis had been made because of focal symptoms and intracranial hypertension after a period of one to two months after a craniocerebral trauma. Angiograms in the three cases had showed deviations of the anterior cerebral artery without sufficient data to demonstrate the nature of the expansive process. In two cases pneumoventriculographic examination showed a deviation of ventricular system and the electroencephalograms revealed depression of electric activity in the hemisphere ipsilateral to the traumatism. Successive roentgenologic examinations showed progressive reduction and even disappearing of the vascular deviation previously found. In one patient a trepanation was performed revealing nothing but cerebral edema. Conditions of the three patients were greatly improved with conservative measures. The object of this paper is to emphasize the difficulties for differential diagnosis with subdural hematoma.