The profound changes in the Polish Armed Forces, primarily related to their professionalization, affect many areas of the military's operation. Nevertheless, the basis for the implementation of any change is the soldier, who is the foundation of the army. What is more, each soldier joining the army structure must go through a stage of adaptation to the new environment, which may prove to be a key element, influencing further service, shaping their attitude and the way they perform their tasks. And although compulsory recruit service was abolished in 2008 and candidates are now volunteers only, the adaptation process is invariably an important stage of military service, which, as the literature in this area indicates, is not often the subject of scholarly consideration. Therefore, the inquiries presented in this article are valuable not only for their subject matter, but also for their uniqueness, stemming from the scope of the study, which includes both soldiers in basic military service and officer cadets, who constitute – after the abolition of universal enlistment – one of the main sources of supply for the army. The aim of the study was to assess the process of adaptation to military service among newly drafted soldiers and to compare the changes that have taken place over 25 years in the perception of this issue. This will allow us to find out (the main research problem) whether the type of military service (compulsory recruit military service versus voluntary recruit military service) has changed young people's perceptions of this difficult period as they enter the ranks of the army. The study primarily used the diagnostic survey method, participant observation, analysis, synthesis, inference and comparison. The results obtained showed that over the course of a quarter of a century, the problems associated with adaptation to military service have remained the same despite the fact that it used to be professional military service and is now voluntary military service. However, the attitude of professional cadres toward newly appointed soldiers has changed. In addition, those who are enlisted are much more likely to be disciplined, as a result of the fact that they are in the army voluntarily and receive their emoluments from the first day of service.