Twelve fungal species were screened for microbial volatile organic compounds (MVOCs): Aspergillus fumigatus, A. versicolor, A. niger, A. ochraceus, Trichoderma harzianum, T. pseudokoningii, Penicillium brevicompactum, P. chrysogenum, P. claviforme, P. expansum, Fusarium solani and Mucor sp. More than 150 volatile substances derived from fungal cultures have been analysed by head-space solid-phase microextraction (HS-SPME). Each species had a defined MVOC profile which may be subjected to considerable modification in response to external factors such as cultivation on different substrata. The cultivation on different substrata changes the number and concentration of MVOCs. Species-specific volatiles may serve as marker compounds for the selective detection of fungal species in indoor environments. Examination of MVOCs from indoor air samples may become an important method in indoor air hygiene for the detection of type and intensity of masked contamination by moulds.