Microorganisms may cause the almost complete degradation of a material structure, even though symptoms of drastic microbial damage may not be apparent macroscopically. Due to their enzymatic activities and outstanding adaptation abilities to various environmental conditions, actinomycetes constitute a particular threat to a variety of materials. They are able to use, and subsequently degrade any substrate, whether this happens in a matter of days, weeks or years. Given the frequency of occurrence and a number of features that enable Streptomyces to growth on materials, more studies should be undertaken on methods allowing for their proper and rapid identification. Taxonomic studies gain particular importance in the case of damaged valuable historic materials. This paper focuses on identification of actinomycetes isolated from various historic and contemporary materials, including textiles, parchment and ceramics. Strengths and weaknesses of approaches that have been chosen for actinomycetes taxonomic studies are described.