postoperative intracerebral hemorrhage after drainage of chronic subdural hematoma is a rarely reported complication; however, its incidence, according to different series may be underestimated.this report presents a 77 year old male patient who, after the drainage of bilateral chronic subdural hematomas, developed an extensive hemorrhage in the thalami, basal ganglia, midbrain and pons, with extension into the ventricles and obstructive hydrocephalus.compression by extra-axial collection decreases cerebral blood flow on the affected hemisphere and alters its vascular self-adjustment. The rapid increase in cerebral blood flow in brain areas with altered vascular self-adjustment appears to be the precipitating mechanism of intracerebral hemorrhage after surgical evacuation of chronic subdural hematomas.