At late December 2017, in pursuance of the previously concluded international agreement on cooperation between Kostroma State University and the Centre for Research of Belarusian Culture, Language and Literature of the National Academy of Sciences of Belarus, a three-year work plan was approved. It included a project aimed at systematisation, scientific interpretation and preparation for publication of the heritage of Gertsel Shklyar, a talented linguist who, in the mid-20th century, contributed a lot to Belarusian linguistics, Russian linguistics, hebraistics. In the course of the project, previously unknown facts of Gertsel’ Shklyar’s biography, summary of the results of his scientific activities during his work at the Belarusian Academy of Sciences (the 1930s) and Kostroma Pedagogic Institute (the 1940s–60s) were disclosed. The linguistic scientist worked actively in the field of Belarusian studies – he participated in the compilation of the Belarusian-Russian and Russian-Belarusian dictionaries, studied Polonisms in the Belarusian language, worked on amending the existing Belarusian-language spelling, on the creation of university textbooks on the modern Belarusian language. Together with Sof’ya Rokhkind, he created the USSR’s first “Yiddish-Russian Dictionary (Jewish-Russian Dictionary)ˮ. Research in the field of the Russian language was mainly dialectological. Gertsel’ Shklyar laid the foundations for the card index of Kostroma regional dictionary. The article examines the results of the international project, highlights the events dedicated to the presentation of the book of selected works by Gertsel’ Shklyar.