Amongst the religious artefacts, the exposed churches, crucifixes and crosses made usually of wood and stone are very often subjected to the micro-/macro-biological attack and colonization. The conservation problems of the cultural/religious heritage affected by this type of deteriorations remain still opened. In this sense, many studies are in progress for finding the most suitable methods, materials and products, with an effective and efficient applicability in the conservation of various monuments and objects with cultural value. In this study the efficacy of a natural derivative from cinnamon against some common biological agents of cultural goods made of wood and/or stone was tested. Five types of organisms (an alga, a cyanobacteria, an imperfect fungus, a macromycete and an insect) were chosen for this research in order to assess the cinnamaldehyde action in for a broad use. The results have shown that phototrophs (Chlorella sp., Chroococcus sp.) and the microfungus (Torula sp.) were more sensitive to cinnamaldehyde with respect to the brown rot fungus (Coniophora puteana), while Hylotrupes bajulus seems to be resistant to this product.