We report a case of interhemispheric subdural empyema following a meningoencephalitis. Ten days after the beginning of his illness a CT scan showed a left interhemispheric subdural empyema with a low density collection, a faintly enhancing rim, multiple very small cortical abscesses and brain edema. The empyema was successfully treated by the direct introduction of a catheter into the left interhemispheric subdural space via a single posterior frontal parasagittal burr hole, irrigation with saline, aspiration of the empyema, and removal of the catheter at the end of operation.