The occurrence of filamentous fungi in 294 samples of drinking water taken from wells and taps near Bratislava was studied. Fungal contaminants were found in 192 samples (44%). 39 genera and 64 species of soil filamentous fungi were identified by routine isolation and cultivation methods. Most of them belong to the Deuteromycetes. In the course of fungal cultivation in Czapek-Dox agar supplemented with 20 mg.l-1 tetracycline, colonies of unknown yellow coloured bacteria were observed.