At the 2009 World Artistic Gymnastics Championships in London in October, Demyanchuk competed with Ukrainian teammates Dariya Zgoba, Valentina Holenkova, and Anastasia Koval, but performed poorly. She was the second reserve for the all-around final after finishing 26th in qualifications. She was 37th on the uneven bars, 46th on beam, and 30th on floor, and did not compete in any finals.