Polish microtoponyms, as they were used in the middle 20th century, are known today mainly thanks to a field names-gathering action probably initiated in 1954 and finished as late as in 1970, carried out by Polish linguists from Krakow, Warsaw, Łódź, Wrocław, Toruń, Lublin and Poznań. The present paper tries to reconstruct its process and the fate of the collected materials, which served as the basis for the incomplete series “Official names of localities and physiographical objects” published in 142 county fascicles between 1963 and 1975. While part of them have been saved and are being published on a digital platform, a lot of information has been irretrievably lost due to the carelessness of its depositaries.