ABSTRACT: The diving beetle genus Microdytes J. Balfour-Browne, 1946 in Thailand, Laos, and Cambodia is reviewed, and five new species are described: Microdyteseliasi Wewalka & Okada, sp. nov. (Thailand, Cambodia), M.jeenthongi Okada & Wewalka, sp. nov. (Thailand), M.maximiliani Wewalka & Okada, sp. nov. (Laos, China), M.sekaensis Okada & Wewalka, sp. nov. (Thailand, Laos), M.ubonensis Okada & Wewalka, sp. nov. (Thailand, Laos). Two species are the first country records: M.balkei Wewalka, 1997 (Laos, Cambodia) and M.wewalkai Bian & Ji, 2009 (Laos). For 12 and 8 species, the first provincial records from Thailand and Laos, respectively, are given. A checklist, a key to the 25 known Microdytes species fro
