Female and male specimens of the Palearctic species, Canthocamptus (Canthocamptus) microstaphylinus Wolf 1905, were found in the coastal zone of Lake Baikal, Siberia. This was the first record of the species in Lake Baikal and the Baikal region. A general description and brief morphological characteristics were made using scanning electron microscopy. The authors compared the principal diagnostic morphological traits of C. (C.) microstaphylinus from Lake Baikal and some water bodies from the European part of Russia (within the Syktyvkar City, Republic of Komi). As a result, specimens from Lake Baikal and the Syktyvkar area were shown to be similar in the structure of their thoracic appendages and caudal rami.