The chokeberry pomace remaining after the pressing of the fruit is a valuable raw material, the processing of which by extrusion-cooking will protect it from spoilage. The chokeberry pomace obtained directly after pressing the juice was ground and processed in a single-screw extruder at different barrel temperatures and different screw speeds. The extrusion processing conditions showed little but significant effect on the total fibre content (TDF) and its soluble fraction (SDF), whereas it had no effect on the content of insoluble (IDF) fractions in the extrudate. A decrease in fat was observed in the extrudates and a favourable change in the fatty acids profile was noted. Vitamins were found to be more susceptible to high temperatures than to mechanical stress. There was a much higher stability of riboflavin relative to thiamine and pyridoxal, a very low stability of tocopherols, and a slightly higher stability of tocotrienols. In the extrudates, the availability of antioxidant bioactive compounds increased.