The museum's mission is defined by the provisions of the official document which is the statute of the Museum of the Polish Army - the parent institution of the "Katyn Museum". The aim of the Museum is to preserve the national cultural artefacts collected, related to the history of the Polish military, to maintain them properly and to make them available for scientific, didactic and educational purposes, so that they serve science and popularise the knowledge of Polish military history.

The Katyn Museum belongs to a unique type of museums - historical and martyrological, i.e. those whose task is to present the Katyn Massacre by means of "specific" material relics [musealia-relics excavated from the death pits - in Katyn, Kharkiv and Mednoye] and numerous documents - in the permanent exhibition of the Museum. As the only one among the national museums, through its permanent exhibition in educational work it tries to realise a programme complementary to the historical education of society, especially of the young generation and to shape patriotic attitudes - depicting all aspects concerning the fate of Poles in the East after 17 September 1939.