The fungal species composition found by using the soil washing technique was affected by the number of species that were isolated from each particle. The particular species that were present were also of importance. Usually, slow-growing fungi were less often isolated if many other species or if heavily sporulating isolates were present. Faster growing species were also affected. Thus, Mortierella pulchella was seldom isolated from a soil particle with another Mortierella species. The use of small particles, where more than one isolate was seldom found, favoured the isolation of slow-growing fungi. The use of small particles with the soil washing technique thus appeared to give a more realistic picture of the fungal community.