1. One hundred soldiers admitted to Bellevue Psychiatric Hospital during 1942 were studied.2. Men who had previous hospitalizations for mental illness and those showing other signs of maladjustment prior to induction tended to break down after a longer period of military service in contrast to men whose pre-induction adjustment was adequate.3. Army life provides precipitating factors which react upon a predisposed individual. However certain situational factors provide an occasion to bring abnormal behavior more closely to the attention of supervising personnel and thereby contribute to the detection of mental symptoms.4. It was shown that the incidence of schizophrenia in men during military service and in civilian patients of the same age group was about equal. These findings applied to first attacks as well as recurrences. No qualitative difference in the psychoses of civilians and soldiers was found.5. The following suggestions for lowering the incidence of psychiatric casualties during military service are made:A. Social investigation consisting of checking files of the Departments of Mental Hygiene to detect and eliminate selectees with previous mental hospitalizationsB. An investigation of the police and social agency records of the selecteesC. A three months probationary period before actual induction into military serviceD. Organization of a special training unit in the replacement training centersE. A psychiatric examination during or after three months of military service of soldiers with poor army adjustment