The fruiting phenology and substrate relationships of myxomycetes in mid-elevation forests of northern Thailand were investigated in five 100 m 2 study plots during the period of October 2004 to October 2005. Collectively, 62 species representing 18 genera were collected. Thirty seven of these are new records for northern Thailand, and one of the species collected (Licea erecta var. erectoides) is known from only a few other localities throughout the world. Few fruitings occurred during the dry season (which extends from November through May), but fruitings were prominent in the rainy season, especially during June and July. Numbers of species recorded for these two months were 45 and 33, respectively. Forest floor litter derived from two trees (Dipterocarpus sp. and Macaranga denticulata) seemed to represent an especially favorable substrate for many of the species of myxomycetes collected in the five study areas.link_to_OA_fulltex