An earthworm inventory was conducted on three islands (Hon Tre, Lai Son and An Son) in the southernmost part of Vietnam. A total of 13 species and subspecies belonging to four genera and two families were collected from 49 sampling sites. The genus Metaphire Sims & Easton, 1972 is dominant with six species and subspecies, Metaphire anomala (Michaelsen, 1907), Metaphire bahli (Gates, 1945), Metaphire houlleti (Perrier, 1872), Metaphire mangophila (Nguyen, 2011), Metaphire kiengiangensis Nguyen & Trinh, 2015, Metaphire peguana laisonensis subsp. nov. Two new species, Polypheretima dorsotheca sp. anov. and Polypheretima insularis sp. nov., and a new subspecies Metaphire peguana laisonensis subsp. nov. are described. Additionally, Amynthas alteradamae (Michaelsen, 1934) and Amynthas tertiadamae (Michaelsen, 1934) are re-described based on fresh material. An identification key to species is also provided.