The first educational environment of every human being is usually the family. This is where the lifelong process of shaping attitudes and acquiring the desired character traits begins. Just as social attitudes are shaped and strengthened on the basis of values derived from the family environment, the ethos of service is built, which develops and strengthens pro-defence attitudes. Nowadays, such attitudes are less and less often seen among young people due to the crisis of values in developed countries and the promotion of a consumerist lifestyle. Ensuring security in the 21st century depends not only on the military or the intellectual potential of citizens, but above all on the extremely important human factor, most often expressed by patriotic pro-defence attitudes allowing for heroic efforts, especially in the event of a real threat. The aim of this article is therefore to show the extremely important role of the family environment in shaping and strengthening pro-defence attitudes among the society of the 21st century. The research was carried out using theoretical methods, such as analysis, synthesis, generalisation, and inference, and using the technique of examining documents and source materials. Particular attention was paid, inter alia, to the need to build pro-defence attitudes among young people and to the educational functions of the family environment constituting the basis for the process of shaping pro-defence attitudes.