C OMPLETE analysis of a series of 84~ penetrating brain wounds constitutes a difficult and long term task. The patients must be studied over a period of years. [ he incidence of epilepsy, late infection, psychiatric problems and estimation of the patients' eventual social worth must be evaluated. Such an analysis is beyond the scope of this report, which deals with the actual treatment, postoperative care, and the immediate results. I t is desired to stress the repetitious nature of the lesions and to present a resultant classification. The surgical problems encountered, and the methods evolved to cope with them, will be described. Dr. Cushing's 3,4 series of 133 penetrating brain wounds during the last war, Ascroft's 1 series of ~9~ such wounds, Cairns '2 report and the Russian experience s have guided our surgical efforts. I t was found, however, that some problems had not been solved and that new and more efficient methods had to be found. The burden of neurologic surgery in the field was heavy, and the tedious procedures, familiar to all neurologic surgeons, had to be shortened. I t became possible finally to operate upon as many as twelve difficult, penetrating brain wounds in twenty-four hours and still maintain Halsted-Cushing technique. A trained team consisting of instrument nurse, anesthetist, and two medical corpsmen, plus invaluable surgeon-assistantst, constituted the direct solution to the demand for speed and efficiency. Surgical technique and routine must be standardized, despite necessary improvisations. This series of penetrating brain wounds is collected from the experiences of the author in the North African, Sicilian and Western European campaigns. They are part of a larger experience dealing with the more simple aspects of wartime neurologic surgery, such as compound, depressed skull fractures, scalp lacerations, closed head injuries, spinal cord and peripheral nerve injuries. They were all operated upon by the author, or by an assistant under the author's direct supervision. ] 'hey were collected from Oran to Tunis, from Licato to Messina, Sicily and from the grim beach-head on Normandy, through France, Belgimn, Holland and Germany. They were operated upon, some times under fire, in Clearing Stations, Field Hospitals, and Evacuation Hospitals. A distorted picture of the magnitude of brain damage caused by war