The fruit of the American cranberry is known for its benefits on human health and its nutraceutical potential. The enrichment of cranberry products with functional phytochemicals may improve their functionality for enhancing health benefits, but this enrichment may be difficult due to the commercial rarity and difficulty of purification of anthocyanins and other phytochemicals from natural sources. The aim of this work was to evaluate the feasibility of the production of a cranberry juice enriched with natural phenolic antioxidant compounds using an ultrafiltration (UF) membrane stacked in an electrodialysis (ED) cell. Total concentrations of proanthocyanidins and anthocyanins increased by 34.8% and 52.9%, respectively, in cranberry juice treated with the EDUF system. Moreover, an 18% increase of the antioxidant capacity of the enriched cranberry juice was obtained by the EDUF treatments. The EDUF process might be used for natural enrichment of cranberry juice with antioxidant phenolics.