Pyrolysis mass spectrometry (PYMS) is a useful typing method for many bacterial and Candida species. We attempted to type Aspergillus spp. by PYMS. Four distinct A. fumigatus isolates could not be distinguished from each other, whereas one A. niger and one A. terreus could. Poor reproducibility was shown using multiple identical cultures of a single A. fumigatus isolate and several isolates of the same DNA type. PYMS is obviously an unsuitable typing method for Aspergillus spp.