In the course of screening for the antimicrobial compounds contained in rare mushrooms, we isolated bisnoryangonin from Pholiota aurivella. The structure of bisnoryangonin was identified by HRESI-MS and NMR spectral data (1-D ( ¹H- and ¹³C-NMR) and 2-D (HMQC and HMBC)). This is the first report on the presence of bisnoryangonin in Pholiota aurivella. The antimicrobial activities of bisnoryangonin against two microbial organisms (Bacillus megaterium and Microbacterium foliorum, which were isolated as food contaminants) were tested. Bisnoryangonin showed more potent antimicrobial activity than butyl-4-hydroxybenzoate which is used as a food additive.