Over 4 years 1.241 fish were examined mycologically. In 182 (14.7%) of them positive results were obtained. Most of the isolates belonged to the following genera: Cladosporium, Saprolegnia, Candida and Penicillium. Fungal infections were correlated with findings of Saprolegnia, Branchiomyces, Pythium, Ichtyophonus and sometimes Cladosporium. Most fungal isolates were etiologically irrelevant for diseases or death.