The article gives an overview of arms and armour in Slovenian museum collections describing these as two significant sources for researching war and military history on Slovenian territory in the Middle Ages. So far, they have not been subject to in-depth research and were, usually, not on exhibition. The biggest collection of arms and armour is preserved at the National Museum of Slovenia, especially finds from the Ljubljanica river, smaller collections are housed by individual regional and city museums, in particular in Ptuj, maribor and Brežice. The tasks of museums are to conserve, to make an inventory of finds and to catalogue objects as a necessary basis for further research that should include scientific and technical analyses, archaeological and historical research. These are the conditions for new modern exhibitions, including reconstuctions or models of arms and devices, with performaces and virtual images.