Soldier’s social adaptation includes his interpersonal relationships with his environment integration into the military community and the ability to fulfill his role in the military environment and to function adequately outside of it. The aim of this study was to establish the dynamics of soldier’s social adaptation during the military service. The study involved soldiers of two platoons of the Armed Forces of Serbia and Montenegro, divided into three groups according to the period of the study: after the first month, after the basic training and at the end of the military service. The instruments applied for the study were sociodemografic questionnaire and Social Adaptation Self-evaluation Scale. Statistical analysis of the obtained data was done using Stident’s t-test. The results of the study that soldier's contentment with his professional role and with the quality of his interpersonal relations was highest during the basic training, but the quality of leisure activities was lowest at the end of the military service.