Polyphenols comprise a diverse group of molecules with antioxidative and anti-inflammatory activities. To compare the antioxidative and anti-inflammatory capacity of Aronia melanocarpa berries (chokeberries), recognized for their high content of anthocyanins, a noncytotoxic isolation method was developed to obtain high-purity anthocyanins in the extract. The antioxidative activity of the extract, the anthocyanin-rich fraction (AF) was determined by 1,1-diphenyl-2-picrylhydrazyl radical and ferric-reducing ability of plasma along with resveratrol as a reference. The immunomodulation properties were assessed in lipopolysaccharide (LPS)-stimulated human monocytes mono mac 6. The isolated AF, containing six different anthocyanins, exhibited a stronger antioxidative capacity compared to resveratrol. Resveratrol enhanced tumor necrosis factor-α and reduced interleukin-10 (IL-10) production by LPS, whereas AF only had a slight effect in reducing IL-10. These results demonstrated that there was no major relationship between the antioxidative effect and immunomodulation capacities of AF and resveratrol. The immunomodulatory activity of the extract is associated with bioactive compounds in Aronia other than its anthocyanins.