Diversity and ecology of desmids (Zygnematophyceae) were studied within eight peat bog sites in the Jeseniky Mts during the years 2006-2009. Altogether, 51 taxa were found in the course of our investigation. A detailed study of spatial distribution of desmids in relation to environmental characteristics was performed. The composition of desmid communities was influenced especially by water table elevation and pH. Among all chemical substances measured and statistically tested, Mg, Ca and Pb concentrations appeared to have a considerable effect. Several remarkable desmid taxa were found and discussed in terms of their occurrence and broad morphological variability.