A biographical essay and a list of the most important publications of Leonid Ivanovych Frantzevych (1935–2024), an outstanding scientist, Doctor of Biological Sciences, Professor, Corresponding Member of the National Academy of Ukraine, founder of the Department of Insect Behaviour Physiology at the Schmalhausen Institute of Zoology of the National Academy of Sciences of Ukraine. The bibliography includes a list of 199 most important publications published from 1959 to 2019. Most of the scientific works are devoted to the issues of ethology, bionics, functional morphology of insects and radiology. The article is illustrated with photographs from the archives of colleagues.