Finding alternative sources of virgin cellulose fibers is of great importance considering that the different types of coniferous and deciduous become insufficient raw material for the paper production. The research presented in this research paper focuses on the possibility of obtaining non-wood cellulose fibers from the straw the most abundant species in Croatia, wheat, barley and triticale, and their use in newsprint papermaking. These paper categories, today, are mostly products made from recycled raw materials, especially old publications. Usage of the primary cellulosic fibre isolated from straw instead of primary wood fibres, in the newsprint papermaking process can refine recovered pulp where fibres are shortened and chemically saturated with chemicals during the recovery process. The numerous researches conducted on a global scale found alternative non-wood raw materials, as a source of cellulose fibres, which were mostly focused on their use in the packaging and corrugated cardboard (liner and fluting papers) production. The chemical composition analysis results wheat, barley and triticale straw, indicate a sufficient amount of cellulose in grain straw and a small amount of incrusting, mainly lignin, inorganic and accessory substances which are an indication of a potential raw material for the cellulose fibre isolation. By analyzing the elements, ICP - MS method, has confirmed that from chemical aspects the triticale straw is the most favourable as a raw material because it contains the smallest proportion of metals such as iron, zinc, aluminium, chromium, nickel, lead and metalloids boron and silicon. The cellulose fibres were isolated from grain straw by alkaline procedure in two ways at precisely defined conditions. The laboratory newsprint handsheets were made from market newsprint paper that is used in some Croatian publishing houses for printing a daily newspaper in larger editions. The optimum share of fibres isolated from grain straw added in the market newsprint pulp, which is normally used for cold set offset printing, was determined on the laboratory newsprint sheets basis on the mechanical tests results and the highest reproduction quality of printed laboratory handsheets by the colours for newspaper printing. The reproduction quality was monitored through smearing resistance analysis. The scientific contribution of the thesis is a research enclosure on the possibility of the cellulose fibre isolated from grain straw in the Croatian region usage in the production of newsprint.