Until the present study, 156 rotifer species had been recorded from different parts of Iran. The present study was designed to fill in some of the gaps in our knowledge on rotifer fauna of Iran and to analyze the geographical data of rotifer records from this area. Given the location of the study on the corner of the Palearctic, we also wanted to understand the influence of neighboring zoogeographical regions on both Khuzestan and the rest of Iran, i.e. the Palearctic.Khuzestan Province, our study area, is situated in the subtropical zone of the southwest corner of Iran (Figure 1) where the province and its freshwater systems, which