The importance of the selection from the psychiatric viewpoint becomes obvious when we examine the data of the U.S. Army during World War II. In spite of the careful selection, all the men can have a combat reaction more or less severe. The early recognition and intensive treatment make possible the recovery of the majority of the cases. The sequelae of the combat reactions are the consequence of the lack of ego capacity for an adjustment even in the absence of the combat stress and, specially, for a civil readaptation. Next to this, and probably as important, are the associated secondary gains which contribute for the perpetuation of the neurosis. Individuals with strongly repressed hostile and aggressive impulses have a gratification for those in the battle situation. This gratification will harm the adjustment of these individuals in the civil readaptation. In the three cases presented these factors contributed for the establishment of a chronic reaction.