In 1909 Vasily Leonov graduated from the 2nd Voronezh Gymnasium. In 1914 he graduated from Military Medical Academy (now S.M. Kirov Military Medical Academy) in Saint Petersburg.
In 1914-1917 Vasily Leonov was a Military Doctor. In 1918-1921 he was a Resident Physician at the Children's Clinic of the Medical Faculty of Voronezh State University. In 1921-1922 he was Vice-Rector of Physiological Institute at Voronezh State University. In 1923 he was Head of the Department of Children's Diseases at Smolensk Medical Institute. In 1924-1930 he was Head of the Department of Children's Diseases at Belarusian State University. Since 1930 he was Head at Minsk Medical Institute. In 1959 he was Head of the Department of Gerontology at the Academy of Sciences of the Belorussian SSR.