Extrusion is a process during which the content of soluble fraction of a dietary fibre increases; this dietary fibre has a hipocholesterolemic and hypoglicemic effect on the human organism. Therefore, the statement that cereals win an additional health promoting quality after having been extruded is correct. The materials used in this study were rye bran extrudates of three varieties of rye: Amilo, Rostockie, and Agrikolo. In the samples investigated, the following parameters were determined: soluble and insoluble fractions of dietary fibre, total fibre content, soluble and insoluble pentosans, total pentosans, and antioxidant activity of methanol-acetone extracts obtained from these extrudates; the antioxidant activity was determined using ABTS^•+. It was stated that the following extrusion parameters applied: moisture of 14% of the initial original material, and temperatures of 120 and 180°C, attributed to the increase in the content of the soluble fraction of dietary fibre, soluble pentosans, as well as to the higher antioxidative activity of rye bran extrudates.