In this study, a very rare water mite Arrenurus berolinenis is described for the first time from Turkey. The species was previously reported from Eastern Prussia (1907), Berlin (1896) and Overijssel (2007). The first description of the female was reported by Smit (2007). We have been reporting Arrenurus berolinenis from Turkey as the fourth report. Here, we have dis-cussed the characteristics of this species by giving measured values of male specimens.