In the course of screening for new metabolites from Basidiomycetes, a new 1-arylpropane-1,2-diol named agaridiol (1) was isolated from cultures of Agaricus sp. Its structure was elucidated by mass spectrometric and NMR spectroscopic investigations. Agaridiol shows moderate antimicrobial activity against Bacillus subtilis ATCC 6633, but no activity against fungi, yeasts and Gram-negative bacteria.