This article is devoted to the publication of the manuscript “Notes about Lithuanian Tatars” stored in the funds of the National Historical Archive of Grodno, Belarus (Nat. Hist. Archive of Grodno. F. 1. – Op. 27. – D. 202. – L. 87–92).The time and place of manuscript creation, as well as the name of its author are not specified, and the scientists working in the archive referred it to 1832. From the Note’s content it is possible to assume that it appeared among Tatar noblemen and was submitted to the Grodno Deputy Assembly not earlier than Alexander I accession in 1801.The author of the document strived to show Tatars’ self-sacrificing faithfulness to interests of Lithuania (and later Poland as well), their full solidarity with the Lithuanian nation, without distinction as of religion; to detrace the evolution of Tatars’ social status equalized with the status of Polish gentry; to underline that Tatars were in demand on both military and civil services even after liquidation of the Polish–Lithuanian Commonwealth’s political independence. Thereby the source reflects the time when Tatars appeared in Lithuania, the reasons for their settlement, octroying them the lands and, finally, – the general milestones of the social-legal integration to the category of Polish gentry and then to the Russian nobility of a peculiar population group – Lithuanian Tatar noblemen.We hope that this source will prove to be helpful while studying the problems referring to the socioeconomic, political-legal plots of history on the Eurasian scale.