Radiocarbon dating of the plant material is important for chronology of archaeological sites. Therefore, a selection of suitable plant samples is an important task. The contribution emphasizes the necessity of taxonomical identification prior to radiocarbon dating as a crucial element of such selection. The benefits and weaknesses of dating of taxonomically undetermined and identified sam-ples will be analysed based on several case studies referring to Neolithic sites from Hungary, Slovakia and Poland. These examples better illustrate the significance of the taxonomical identification since plant materials of the Neolithic age include only a limited number of cultivated species (e.g. hulled wheats) and typically do not contain remains of late arrived plants (e.g. Carpinus betulus and Fagus sylvatica). For more accurate dating results cereal grains, fruits and seeds, which reflect a single vege-tative season, are preferred. Among charred wood, fragments of twigs, branches and external rings should mainly be taken into account, while those of trunks belonging to long-lived trees should be avoided. Besides the absolute chronology of archaeological features and artefacts, radiocarbon dating of identified plant remains might significantly contribute to the history of local vegetation and food production systems.