As a result of the phytochemical analysis of cloudberry leaves, one new (1) and four well-known natural compounds (2 - 5) were isolated and their structures established. Compound 1 4-O-α-L-arabinofuranosylellagic acid and compound 2 (-)-epicatechin belong to the class of tannins. The rest of the isolated compounds are glucuronic glycosides of flavonoids - quercetin-3-O-β-D-glucuronide (3), quercetin-3-O-β-D-2 -galloylglucuronide (4) and kaempferol-3-O-β-D-glucuronide (5). Compounds 4 and 5 were found in Rubus chamaemorus L. for the first time. Predictions of the biological activity spectra for the isolated compounds 1 - 5 using the PASS program provides insights regarding most promising directions for studying their biological activity.