The historical development of bryophyte studies in Thailand is reviewed. Two historical periods are distinguished: the first period, 1899–1977, during which collections were made and studies were carried out by foreign botanists/bryologists in the framework of expeditions and the Flora of Thailand project; and the second one, 1977 to the present day, in which bryophyte work has been done mainly by Thai bryologists. In total, two species of hornworts, 20 of liverworts, and 63 of mosses have been described as new to science based on collections from Thailand. Of these, 48 are hitherto only known from Thailand and may be considered endemic to the country. Future work should focus more on taxonomic treatments of individual genera although further area-based research is also necessary.