A new species of the genus Hirudinaria from Thailand is distinguished from its congeners by the dorsal colour pattern and reproductive structures. Scanning electron microscopy provided novel information on the jaw morphology of Hirudinaria bpling, sp. nov. and also of the previously described Hirudinaria manillensis. During the study, the genus name Hirudinaria in reference to leeches was found to be a homonym and, in this case, precedence is reversed. Phylogenetic analyses based on the nuclear genes 18S rDNA and 28S rDNA as well as the mitochondrial genes 12S rDNA and cytochrome c oxidase I, supported the new species as nested within the monophyletic genus Hirudinaria. Two individuals from the Caribbean, nominally identified as H. manillensis, included in the phylogenetic analyses were strongly supported as members of that species.