Introduction. The bird cherry (Padus avium Mill.) belongs to the Rosaceae family and is common in Poland. In various parts of the plant, among others, flavonoids, anthocyanins, phenolic compounds, cyanogenic glucosides, tannins, essential oil, organic acids and sugars are present. They determine astringent, anti-inflammatory, estrogenic, anesthetic, antidiabetic, cytotoxic and antibacterial properties. Aim. Determination of antioxidant activity and sum of polyphenols in leaves, flowers, fruits and young branches of bird cherry, as well as confirmation of the presence of selected flavonoids and phenolic acids. Material and methods. The research material was leaves, flowers, fruit and young twigs of Padus avium, collected from a natural site in the Noteć Forest (near Sieraków). The contents of the sum of polyphenols in the prepared extracts were determined by spectrophotometric method using the Folin-Ciocalteu (FC) reagent and the antioxidant activity by the DPPH radical method and the FRAP method, and the presence of selected flavonoids and phenolic acids was confirmed by thin-layer and paper chromatography. Results. In water and methanol extracts, the highest content of polyphenols (%) in terms of coffee acid was found in leaves (6.91 ± 0.30%; 9.02 ± 0.34%), and the lowest in fruits (2.05 ± 0, 11%; 3.11 ± 0.11%). Water and methanol extracts from leaves showed the highest antioxidant activity and the weakest water extracts from fruit (DPPH and FRAP methods). 1D-TLC, 2D-TLC and tissue paper (PC) analysis revealed the presence of rutoside in flowers and twigs, hyperoside in leaves, flowers, fruits and twigs, and most likely ferulic and vanillic acids in fruits and twigs, chlorogenic and coffee acids in all raw materials from the bird cherry. Conclusions. The highest content of polyphenolic compounds was determined in black cherry leaves, both in water and methanol extracts. The water and methanol extracts from the leaves showed the strongest antioxidant activity. The presence of rutoside, hyperoside and some phenolic acids was confirmed in the tested raw materials.