A study of saprotrophic microfungi associated with the palm Calamus sp. in Thai forests yielded 88 species, with 40 ascomycetes (45.5), and 48 anamorphic taxa (54.5) from 212 fungal collections. The most common fungi were Tetraploa sp. (14.1 of all records), Morenoina palmicola (11.8), Circinoconis paradoxa (5.2), Diaporthe sp. (4.7), and Helminthosporium sp. (4.7). The percentage of fungi occurring on dry versus damp materials were 68.5 and 31.5, respectively, with 61 of fungi occurring on petioles and 39 on rachides. The fungi occurring on Calamus sp. are compared with those recorded on other palms in Australia, Brunei, Hong Kong and Thailand.