The superfamily Rhodacaroidea comprises six families, including Digamasellidae, Halolaelapidae, Laelaptonyssidae, Ologamasidae, Rhodacaridae and Teranyssidae. Predatory mites of the family Ologamasidae occur in soil and organic materials, such as humus, compost, carrion and seaweed, as well as nest of small mammals. The family currently includes about 470 described species arranged in 44 genera. Most of the genera and species of ologamasids have been reported from the Southern Hemisphere. Till now, few species of only four genera of the family have been recorded from Iran, including the genera Gamasiphoides Womersley, Gamasiphis Berlese, Sessiluncus G. Canestrini and Stylochirus G. & R. Canestrini. One of the smallest genera of Ologamasidae is Periseius which has been erected by Womersley in 1961and currently includes only five described species worldwide. Some of the diagnostic attributes of Periseius are as follows: podonotal (with 21–23 pairs of setae) and opisthonotal shields (with 19–21 pairs of setae) separated; three pairs of presternal platelets present; sternal shield fused only by a narrow strip to endopodal platelets between coxae III-IV; peritremes anteriorly extending to anterior level of coxae I; peritrematal shields posteriorly widely fused to ventrianal shield; genua I, III and IV and tibia IV with 13, 9, 10 and 10 setae, respectively. In a faunistic survey on mesostigmatic mites in mangrove forests of Qeshm Island, northeastern of the Persian Gulf (2017–2018), edaphic mite specimens were extracted from soil samples using Berlese-Tullgren funnels, cleared in Nesbitt's fluid, and then mounted in Hoyer's medium on microscope slides. Among the collected specimens, one species with diagnostic characters of the genus Periseius was identified and based on our knowledge about the described species of the genus considered as new for science. This is the first record of a species of the genus Periseius from Iran.