The phytochemical characteristic analysis of a group of 30 haskap berry genotypes was carried out bearing in mind the concern for the consumption of food with high nutraceutical value that helps maintain good health. Phytochemical fruit composition and antioxidant activity were assessed by the Folin–Ciocalteau, spectrophotometric, DPPH (1,1-diphenyl-2-picrylhydrazyl) as well as ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) method. Evaluation of antioxidant activity was referred to as the Trolox equivalent. The observed differences in the content of phenolics, flavonoids, vitamin C and antioxidant activity allowed us to select genotypes which, due to the high level of the analyzed compounds, are particularly recommended in everyone’s diet. In addition, the analysis of the prospects of increasing the analyzed phytochemical properties, estimated by parameters such as heritability and genetic progress, indicates the effectiveness of breeding in relation to each of the analyzed traits. The results of the presented research can be used in the implementation of future breeding programs for this valuable species.