Abstract
The diplopod genus Leptoiulus Verhoeff, 1894 is new to the fauna of the Asian part of Russia, due to the discovery of L. tigirek sp. nov. from the south-western part of the Altai Province, Siberia. A description of the new species and information on its habitats, numbers and locomotor activity as well as comparison with the European Leptoiulus trilineatus (C.L. Koch, 1847) are presented.