The article is devoted to identifying the role of the Finnish scientist Yrjö Jooseppi Wichmann in the formation and development of Udmurt folkloristics. In Udmurt sciences, Yrjö Wichmann is represented as a linguist, one of the founders of comparative historical permistics, who made a huge contribution to Udmurt dialectology, historical phonetics, historical lexicology and etymology. However, the role of the Finnish scientist as a folklorist, who laid the foundations for the principles of recording and publishing folklore material, including music, has not yet been appreciated in Finno-Ugric studies. He made two long trips to the Udmurts in order to study some Udmurt dialects, there he recorded a significant corpus of samples of Udmurt speech. The corpus is composed of different genres of Udmurt folklore: songs, conspiracies, prayers, riddles, legends, etc., published in two volumes of "Wotjakische sprachproben" (1893; 1901). In addition, possessing musical notation, he recorded and published a corpus of melodies of Udmurt ritual songs, which have become a valuable source for modern comparative research. A rare success of the Finnish researcher should be considered records of rare instrumental tunes that accompanied pagan prayers. Publishing and describing folklore material, Yu. Vihmann, as a linguist-dialectologist, used the areal method, and for the first time used the folkloristic principles of classification, dividing the folklore material of each dialect into genre-thematic groups. At the same time, Yu. Wichmann, the first scientist in the history of Udmurt folkloristics, applied ethnomusicological methods in describing the genre system, the structure of melodies and the performing manner. Yrjö Wichmann rightfully occupies a prominent place in the history of Udmurt folklore studies. To a certain extent, he was ahead of his time, using the methodology and principles of working with folklore material, which have become fundamental in modern Russian folklore studies.