Phytochemical analysis of cloudberry leaves isolated one new (1) and four well-known compounds (2-5) and established their structures. Compounds 1 (4-O-alpha-L-arabinofuranosylellagic acid) and 2 [(-)-epicatechin] belonged to the tannin class. The rest of the isolated compounds were the flavonoid glucuronic glycosides quercetin 3-O-beta-D-glucuronide (3), quercetin 3-O-beta-D-2 ''-galloylglucuronide (4), and kaempferol 3-O-beta-D-glucuronide (5). Compounds 4 and 5 were isolated from Rubus chamaemorus L. for the first time. Predictions of the biological activity spectra for isolated 1-5 using the PASS program provided insights regarding the most promising directions for studying their biological activity.