The biological activity of Ledum palustre L. essential oil is determined by the content of monoterpenes, sesquiterpenes and their oxygen-containing compounds. But the composition of Ledum palustre essential oil differs not only in plants growing in different regions, but also in plants growing in the same region. The purpose of this work is to determine the component composition and study the biological activity of individual fractions of the essential oil of Ledum palustre, growing in the Krasnoyarsk region. The component composition of the fractions obtained by hydrosteam distillation was determined by gas chromatography-mass spectrometry. Antimicrobial activity was studied by the disk diffusion method against strains of Staphylococcus aureus (MSSA), Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Antiradical activity was assessed using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The dominant components of wild rosemary essential oil fractions are p-cymene, trans-pinene, terpinen-4-ol, δ-cadinene, germacron and β-eleenone. The first two fractions of essential oil, enriched with monoterpenes, showed the highest antimicrobial activity. A correlation was revealed between the value of the antiradical activity of the fractions and the content of sesquiterpene hydrocarbons in the fraction. The essential oil of Ledum palustre is promising for further studies of its biological activity.