The article is devoted to the study of methods of creating surnames from the appellative tаtо. An overview of the scientific works of domestic linguists on the theoretical and applied aspects of the study of Ukrainian surnames was made (see, for example, the works of I. Varchenko, V. Horpynych, and I. Kornienko, L. Masenko, Yu. Pradid, M. Khudash, P. Chuchkа, etc.), their lexicographic study both in general (V. Demchenko and I. Lopushynskyi, A. Zosimov, Yu. Redko, etc.), and of special regions of Ukraine in particular (H. Arkushyn, V. Horpynych, Yu. Novikova, L. Kravchenko, P. Chuchka, etc.). Even a short review of the scientific investigations of Ukrainian scientists gives reason to claim that the microgroup of surnames “Tato” was studied casually, in connection with the study of other problems, and was not the subject of a separate scruptulous description. The purpose of the proposed article is to investigate the place of the microgroup of surnames “Tato” in the system of surnames common in Ukraine, to describe the methods of their creation, to distinguish the affixes with the help of which the surnames of the analyzed microgroup were created. Achieving this goal involves solving the following tasks: 1) to isolate the microgroup of surnames “Tato” from the system of surnames common on the territory of Ukraine; 2) to analyze the ways of creating surnames from the appellatives tаtо; 3) to determine their regional prevalence in Ukraine. From the system of surnames common in Ukraine, a microgroup of surnames “Tato” has been singled out, which includes 67 surnames, which are borne by 5,236 residents of Ukraine. The material for the study was surnames selected from dictionaries of Ukrainian surnames, materials of the “Tato” site, which records 876,000 surnames of residents of Ukraine. 12 surnames became the basis for the creation of 49 new surnames, and no new surnames were formed from 3 surnames derived from the surname tаtо. The most common surname of the studied microgroup is the surname Tatusevych (217 speakers), and the most derived surnames are formed from the surname Tatkо (11 surnames). The analysis of the actual material gave reasons to claim that the main method of creating surnames derived from the surname Tatо is the suffixation: Tatus - Tatus-k-o, Tatul-a - Tatul-chenk-o, Tatk-o - Tatk-ovets and others (a total of 51 surnames). It is noted that the suffixes -ov -enk- (by 7 cases) are most often used to create new surnames. 9 female surnames are formed in an inflectional way from the bases of male surnames: Tatk-ov - Tatk-ov-a, Tatk-in - Tatk-in-a, Tatus-ov - Tatus-ov-a, etc.