The aim of this study was to determine the frustrations that prevent soldier's successful adaptation to the military environment in the first three months of military duty. The sample consisted of 200 adapted (group A) and 400 maladapted (group NA) soldiers. The applied instrument was the Adjustment questionnaire. It was concluded that the most important cause of frustration was the problem of establishing the interpersonal relationship of soldier and his comrades in the unit. The presence of the actual factor of decompensation was also important, in the sense that it could disqualify for military duty, temporarily or permanently, even a well adapted soldier. Commanding officers and comrades could positively influence the socialization of a personality, by helping the less sociably adaptable soldiers in their adaption to the military environment.