Methylripariochromene A (6-acetyl-7,8dimethoxy-2,2-dimethylchromene), a root constituent of Eupatorium riparium, displayed antifungal activity against five ofthe seven fungal species tested. The chromene showed a toxicity to the fungus Colletotrichum gloeosporioides, a tropical pathogen, comparable to that of a commercial fungicide, although the chromene appeared to be fungistatic.