none New data on the biology of Diptera associated with fungi are presented in this paper based on the investigations in 1998-2000. Altogether 67 species of Diptera (excl. Mycetophilidae) belonging to 22 families were reared from 82 species of fungi collected in Czech and Slovak Republics. Five species of parasitoids from the families Braconidae and Eucoilidae (Hymenoptera) reared from their hosts are also recorded. Thirteen species of Diptera and 4 species of Hymenoptera are recorded for the first time from Czech or Slovak Republics. The first record of a host fungus is given for the following species: Keroplatus tuvensis A.ZAITZEV, 1991; Scatopsciara neglecta MENZEL & MOHRIG, 1998; Monardia modesta (WILLISTON, 1896); Spaniocera squamigera WINNERTZ, 1863; Psychomora vanharai JEZEK, 1995; Agathomyia antennata (ZETTERSTEDT, 1819) and Seri obscuripennis (OLDENBERG, 1916). Hymenoptera; Dipteran hosts; Records including new geographical records, hosts associated with fungi; Czech Republic; Records from dipteran hosts associated with fungi Aspilota caudata; Orthostigma sculpturatum; Synaldis globipes (Braconidae ); Kleidotoma bicolor (Cynipidae ); Czech Republic; New record, dipteran host associated with fungus