This paper summarises the inventory of biota of the western region of Ukraine in the web resource Data Centre ‘Biodiversity of Ukraine’ (DCBU) (http://dc.smnh.org), a growing biodiversity platform launched on 25 May 2017 and which organises knowledge on the biodiversity of Ukraine. The main objective and originality of DCBU is to aggregate curated biodiversity data of different kinds (e.g. scientific and vernacular names, data records of species, their geotagged geographical and biotopic distribution, conservation categories, and representation in protected areas of Ukraine). The database of the resource is primarily filled with data concerning 7 oblasts (Volyn, Rivne, Lviv, Ternopil, Ivano-Frankivsk, Chernivtsi, and Zakarpattia oblasts) of the western region of Ukraine, which is discussed in this article. Currently, the following number of species of living organisms has been recorded for the mentioned oblasts of the region: Volyn Oblast—1311 species/80 protected species listed in the Red Data Book of Ukraine, Rivne Oblast—535/47, Lviv Oblast—3163/211, Ternopil Oblast—1081/164, Ivano-Frankivsk Oblast—1942/157, Chernivtsi Oblast—672/87, and Zakarpatska Oblast—2125/149. Taxonomic accounts in the DCBU cover 5 kingdoms (Chromista, Protista, Plantae, Fungi, and Animalia), 22 phyla, 81 classes, 283 orders, 1292 families, 4741 genera, and 11 763 species. DCBU enables the following operations to be accomplished: to create species lists of different taxonomic rank of separate territorial regions and water bodies of the country and also of different time intervals, to create lists of protected and endemic species and of those that are deposited in collections of scientific institutions; to find a particular specimen according to the inventory number, to create species lists according to the type of recording/collecting, collected or determined by certain specialists, to search for literature sources concerning the Ukrainian biota, and to advanced search for all mentioned parameters as well. The accumulation of information on biodiversity, the possibility of its searching and the free access would promote the development and speed-up of scientific research, the effective control of the ecological state of the environment by the public, and sustainable development.