Berlin strains of Histomonas meleagridis were subcultivated to produce cyst-like stages. These strains were studied for their ITS 1 and 18S rRNA properties and compared with sequences in data banks of other H. meleagridis strains, Dientamoeba fragilis, and some species of the genus Trichomonas and relatives. The Berlin isolates that had previously been shown to be able to develop cyst-like structures (Munsch et al. 2008) represent a significant cluster among the published data of other Histomonas meleagridis isolates and thus the formation of cysts might be a common feature that would open further possibilities of transmission.