Investigations on microfungi on Pandanus odorifer (Pandanaceae) from southern Thailand resulted in the discovery of three new species of Hermatomyces (Lophiotremataceae). Phylogenetic analyses of combined LSU, ITS, SSU, RPB2 and TEF1 sequence data showed that our new taxa cluster with Hermatomyces species and were well separated from Aquasubmersa and Lophiotrema species in Lophiotremataceae. We introduce the new species, Hermatomyces krabiensis, H. pandanicola and H. saikhuensis, with illustrated accounts. Evidence for demarcation of the three new species is provided using morphology and phylogenetic analyses. This is the first report of Hermatomyces on Pandanus species.