Spring fens are unique habitats of dipteran larvae taxocoenoses, especial with respect to their diversity as well as abundance. Eight sites situated in the eastern part of the Czech Republic were sampled in order to study the composition and variability of these taxocoenoses. Totally, 25 families and 93 taxa of dipteran larvae were identified (chironomids were identified to the family level only). Three groups of study sites were distinguished using cluster analysis: tufa-forming fens, peat-forming fens, and Sphagnum fens. Dipteran assemblages of these types were described and discussed in details.