The aim of the research was to compare the oat flour, constituting remains after the beta-D-glucans concentrate production, with common wheat and rye flours and selected hydrocolloids in order to check its applicability as a food thickener. Presented findings concern comparison as well as determination of the influence of applied polysaccharides hydrocolloids (xanthan - GX and guar gum - GG) on mechanical spectrum, viscosity, hardness and flow curves of pastes made from wheat, rye and oat flours, respectively. The highest viscosity was noted for paste of oat flour at 92 degree Celcius and also after cooling to 30 degree Celcius. Diverse influence was observed for hydrocolloid additives. The synergistic interaction phenomenon was also observed in the case of both applied hydrocolloids. The paste of oat flour may be characterised by the smallest hardness, which could have an important influence on consumers’ sensory analyses. The phenomenon was hydrocolloid-independent. The paste of oat flour was characterised by the highest pseudoplasticity, thixotropy as well as smaller ability for structure rebuilding. The flow behaviour was not modified by hydrocolloids additives but the thixotropy was reduced in the case of guar gum addition (reduction up to 50%) and xathan (reduction up to 80%). The results of mechanical spectrum research clearly show that all flour pastes were almost frequency-independent. Additionally we have noted that oat flour paste showed the lowest value of tangent delta (G"/G’) in the whole tested frequency range when compared with other tested samples. This testifies that such a paste has the strongest and the most stable structure even without hydrocolloids.