The demand for wood as raw material for papermaking industry increases almost daily due to the global population increase. Although wood is a renewable resource its annual growth rate is far from adequate in terms of satisfying the papermaking industry needs for raw material quantity. Therefore, alternative fibres sources are needed today and especially for future generations. One of such sources is straw as crop residue. Willing to get closer insights in the possibility of cereal straw use as an alternative fibres source for papermaking, in this paper the lengths of fibres isolated from three most commonly used wood species (e.g. common beech, Norway spruce and black poplar) were compared with those of fibres isolated from wheat, barley and triticale straw. The fibres length was selected as it is the main anatomical characteristic governing the possibility of fibres use for papermaking production. Obtained results indicate that straw fibres length (≈ 0.9 mm) is substantially shorter than wood derived fibres (> 1 mm) and therefore such fibres could be used solely as wood fibres substitutes or complements in the production of certain types of papers.